Multi-layer material with high strength at high temperature for heat exchanger sheets

FIELD: metallurgy.

SUBSTANCE: invention relates to method of production of the multi-layer material for high temperature brazing, and can be used, for example, to manufacture heat exchange sheets. The method ensures core layer out of first aluminium alloy containing in wt %: 0.5-2.0% Mn, < 1.0% Mg, < 0.2% Si, < 0.3% Ti, < 0.3% Cr, < 0.3% Zr, < 0.2% Cu, < 3% Zn, < 0.2% In, < 0.1% Sn, and < 0.7% (Fe+Ni), Al rest and <0.05% each of inevitable admixtures; assurance of the barrier layer out of second aluminium alloy containing in wt %: < 0.2% Mn+Cr, < 1.0% Mg, 1.6-5% Si, < 0.3% Ti, < 0.2% Zr, < 0.2% Cu, < 3% Zn, < 0.2% In, < 0.1% Sn and < 1.5% (Fe+Ni), Al rest, and < 0.05% each of inevitable admixtures; joint rolling of layers; heat treatment at temperature from 300 to 550°C for time period necessary to balance content of Si to 0.4-1% both in core layer, and in barrier layer; rolling of the multi-layer material to final thickness with compression degree from 8 to 33%.

EFFECT: invention increases strength properties, especially creeping and fatigue strength, and corrosion resistance of the multi-layer material.

24 cl, 7 dwg, 4 tbl, 3 ex

 

[0001] the Present invention relates to a method for manufacturing a multi-layer material ("sandwich"), designed for high temperature soldering (hereinafter for brevity referred to simply as by soldering) to the method of manufacturing a brazed product and to the use of brazed products. The present invention also relates to a multilayer material obtained from the first method, and to a brazed product obtained by the second method.

Background of the invention

[0002] aluminum is a material that is often used for the manufacture of soldering. The aluminum can to alloy the introduction of various alloying elements such as Mn, Mg, Ti, Si, and the strength of the aluminum alloy is influenced by the release of particles or alloy materials forming a solid solution with aluminum.

[0003] the Material for soldering of the specified type can be given a high strength after brazing by cold forming before soldering, namely, by rolling or stretching at a temperature below 200°C, which increases the strength, and this should be done so that he didn't lose strength increase when soldering. This means that the material must be completely prevented recrystallization during heat treatment, which is accompanied by soldering. In addition, such material can be predavac� high fatigue resistance and creep for use at high temperature, component of up to 300°C inclusive. This high strength at high temperature is created as a decrease in the driving force of recrystallization by choosing a sufficiently low degree of deformation during cold forming or increase in slow-wave power by creating a large enough number of particles per unit volume.

[0004] the material for soldering, you can apply a layer of solder alloy with high silicon content. During the soldering process the material is brought into contact with another part and heated in a furnace for brazing. High silicon content in the layer of the solder causes the solder layer to melt at a lower temperature than the underlying core layer flow due to capillary forces and surface tension differences and form a brazed seams with another item.

[0005] Another option of material for brazing does not contain any layer of solder, but solder it to the material with such a layer. For example, such material can be used in so-called fins or fins in heat exchangers such as automotive radiators, which are bent from thin aluminum sheet. In the manufacture of the heat exchanger fin is applied to the clad solder tube and then heated in a furnace for brazing, resulting in a layer of solder on the tube melts, spreads due to capillary�forces and differences in surface tension and forms a solder joint between the fins and tube.

[0006] the Main function of the ribs in gas-liquid heat exchanger, such as an automobile radiator, is to conduct heat from the liquid in the tube to the gas. Ribs often perform additional functions. Soldering is carried out at a very high temperature so that the material can get creep deformation only due to the mechanical stresses due to its own weight. The edges should not become so soft that they crushed, and should preserve the shape of the heat exchanger. Corresponding to the ability of the ribs, the so-called "SAG resistance", measured by pinning strips of a certain length, such as 50 mm, horizontally at one end in a furnace which had been heated to 600°C. the Deflection of the loose end was measured after cooling of the furnace. Also important is the ability of the heat exchanger to withstand the high pressures that may occur in the tube during operation, and this ability provides edges to withstand this high pressure. If the ribs have good strength even under high temperature, the tube can be thinner, which means less weight of the heat exchanger.

[0007] If the solder material details paracrystalline when heated to soldering temperature before reaching the melting temperature of the solder, silicon from the solder penetrates into the exposed�my soldering material. In a thin sheet, such as edges, this is due to the risk of melting or crushing, or, alternatively, the formation of incomplete or unsatisfactory solder joints with large pores. The penetration of silicon occurs by diffusion, melting of the outer layer or so-called "gigaplane migration" (see, e.g., A. Wittebrod, S. Desikan, R. Boom, L. Katgerman, Materials Science Forum (materials science Forum), 2006, vol. 519-521, pp. 1151-1156).

[0008] Thus, the above material for brazing, which is not paracrystalline during soldering, must have a barrier layer. A fitting name material consisting of several layers, the multilayer material ("sandwich"). The function of the barrier layer is to reduce the penetration of silicon from the material of the solder to the underlying core material during brazing and thereby ensure the formation of good solder joints, so that the core material does not start to melt. The penetration of silicon occurs especially easily at grain boundaries of polycrystals. Therefore, in the barrier layer, the formation of large grains, that was not enough of grain boundaries.

[0009] One problem with conventional high-strength material for soldering, such as a material with a high content of manganese, is that its corrosion properties are not the best. Intermetallic particles with iron�, manganese and aluminum are more noble than the surrounding aluminum matrix, which leads to pitting corrosion in damp conditions. Commercially pure aluminium, contains only iron and silicon as alloying materials and also having a low iron content, has considerably better properties in this respect. Therefore, the barrier layer and core layer can intentionally be so that the multilayer material has good corrosion properties.

[0010] If the tubes in air-water heat exchangers corrode, they leak that must be prevented. Therefore, in the alloy of the ribs is often injected zinc so that they had a lower electric potential with respect to the tube and provided so-called cathodic protection. Of course, this leads to greater General corrosion on the edges. But this may be acceptable, taking into account the fact that should not occur intergranular corrosion and pitting corrosion, which leads to accelerated dissolution of the ribs. One additional method of improving the corrosion properties is to increase the electrochemical potential of the core layer. This can be accomplished, for example, using copper, manganese or other alloying material, which increases electrochemi�technical capacity in the solid solution and that translates into solid solution during the soldering process.

[0011] One problem with known types of material for brazing is that they do not have sufficient fatigue strength and creep resistance at high temperatures. If during the test, set a high temperature above 200°C, and the material is exposed to high voltage, service life due to fatigue with the high creep resistance of the material is also limited. Since the intermetallic selection make a significant contribution to the strength at high temperatures, it is important that they are sustainable and not excessively dissolved quickly over time. This is especially important for the core material, which is not paracrystalline, since the allocation of slow the progress of recrystallization.

[0012] Two examples of products that require the improvement of the fatigue strength and creep resistance at temperatures above 150°C and up to 300°C, are intercooler and exhaust gas coolers for recycling in automotive engines. These products are usually made by soldering multilayer material. Increasing demand for automotive engines in respect of reduced pollutant emissions and increased efficiency means that the data near the coolers are�activities that the ever-increasing operating temperatures and gas pressures. This is problematic because the existing multilayer material does not satisfy these requirements of strength. Conventional automobile radiators, which do not reach operating temperature more than 100°C, today, are made of relatively thick material for durability reasons. The increase in mass leads to high fuel consumption. A large amount of material used in the radiators, also makes it expensive for them to manufacture. Despite the fact that the ribs are thin in comparison with the tubes and other parts, automobile radiator, they still make up a significant part of the mass of the radiator, perhaps 40%, and thus, for them, is very important to have good strength at the operating temperature so that it was possible to reduce their thickness.

[0013] the Above problem was solved for the tubes and end plates of heat exchangers as described in WO 2009/128766. In this way, the core layer has such a composition that it is not paracrystalline during soldering. To prevent the penetration of silicon from the solder in the medullary layer, is applied by rolling the barrier layer, consisting of aluminum alloy, which paracrystalline in large grains during brazing. One problem is that it may be difficult to cause the adhesion of the barrier layer with the heart�Ong layer during hot rolling, if between the core layer and the barrier layer there is a big difference in the deformation resistance and if the barrier layer is very thick. Butoxide aluminum surface is very quickly covered with oxide when it comes into contact with air. To ensure the grip, as on the core layer and the barrier layer must be created on the metal surface without oxide, the resulting contact of one metal with another. This is achieved by increasing the surface by rolling, if both layers are deformed. For example, if the core layer is much harder than the barrier layer, the core layer will not be deformed.

[0014] In the manufacturing process of the barrier layer plate interfere on one or both sides of the ingot from the alloy core. To obtain good performance in the industrial process rolling total thickness of this multilayer stack is 60 cm Then we need to start rolling with relatively small reductions in each pass of rolling. Since the ratio of the diameter of the work rolls to the thickness of multilayer stack is small, this means that the thickness reduction and, therefore, increasing the surface occurs near the surfaces of the multilayer package. If the barrier layer is thick, the increase in surface � the boundary layer between the barrier layer and the ingot of the core is small, and it is difficult to ensure the mutual adhesion of the layers. Even more significant problem is that the thickness reduction occurs on the surface, therefore, the barrier layer is lengthened more than the core layer. As a result, the barrier layer is extruded front and rear of the core layer. Then these protruding parts are cut, which reduces the efficiency of the process. In addition, the barrier layer is extruded around the edges outside of the core layer, which means the variable thickness of the barrier layer the width of the finished sheet. Consequently, the rolled edges of the sheet must be cut off and discarded, as they are the thickness of the barrier layer is excessively small. This further reduces the efficiency of the process. Of course, if the barrier layer is softer than the core layer, which often is the case, the problem of bad performance is additionally enhanced. This problem becomes even more serious for very thin sheets, such as in the ribs of the heat exchangers which thickness is often less than 0.1 mm and can be as low as 0.05 mm. This means that in order for the barrier layer worked, which requires a thickness of at least 0.007 mm, it will be a significant part of the total thickness. Then it will be difficult in the traditional method of making thin sheets �La exchangers the hot rolling process to obtain good performance, especially if the core layer is much harder than the barrier layer. If the thickness of the barrier layer is more than 20% of the total thickness, it is difficult in General to ensure mutual adhesion of the layers during the rolling process.

[0015] the Material becomes solid during rolling in the first place, due to the moisture content of many solid intermetallic particles. Alloying elements in solid solution also increases the deformation resistance. In the multilayer material, the core layer should contain a lot of particles so as to prevent recrystallization, while the barrier layer should contain few particles to precrystallization in large grain size at a relatively low temperature. Thus, the difference of hardness between the layers can be great when they are rolled together, and this should be avoided to obtain good performance.

Summary of the invention

[0016] One primary object of the present invention is to propose a multilayer material for brazing, which can be produced with high productivity and which has high strength both at low and at high temperature, especially in relation to creep and fatigue. This problem is solved the way�m the manufacture of a multilayer material for brazing in accordance with independent claim 1 of the claims. Embodiments of the invention are characterized in dependent clauses 2-9 of the claims.

[0017] This object of the invention is to propose a multi-layer material having good corrosion properties, in addition to the above-mentioned high strength. This problem is solved according to the invention that the electrochemical potential is reduced to the surface, and those that open to the outside surface, the so-called barrier layer, brazed heat exchanger contain few intermetallic particles.

[0018] the Invention also includes a method of manufacturing a multi-layer material for brazing, which provides high performance in the process of rolling and high strength multi-layer material both at low and at high temperature. This is possible due to the fact that can be used for thinner material, which means saving of material and, in addition, in the case of heat exchangers for vehicles, weight reduction, and hence the reduction of fuel consumption.

[0019[ This object of the present invention is to offer a brazed product consisting of a multilayer material having a high strength both at low and at high temperature. This problem is solved by a method of manufacturing a brazed product according to paragraph 10 of the formula image�etenia. Embodiments of this method are characterized in dependent clauses 11 to 14 of the claims.

[0020] the Invention also relates to the use of a brazed product manufactured according to the aforementioned method, for operating temperatures above 150°C, preferably above 200°C and most preferably above 250°C.

[0021] the Brazed product manufactured according to the method described above, can also preferably be used at lower operating temperatures, e.g. up to 100°C, it is possible to use thinner material than usual to save on the cost or mass of the source material and to reduce fuel consumption.

[0022] the Invention provides a multilayer material for brazing comprising a core layer of a first aluminum alloy and a barrier layer of a second aluminum alloy, wherein the barrier layer and the core layer have almost the same resistance to deformation before the joint rolling, and this multi-layered material can be obtained using the following steps:

- providing a core layer of a first alloy, which contains (in wt.%): Of 0.5-2.0%, preferably of 0.8 to 1.8%, most preferably from 1.0 to 1.7% Mn, ≤ 0,2%, preferably ≤ 0,1% Si, ≤ 0.3% of Ti, ≤ 0,3%, preferably ≤ 0.2% of Cr, ≤ 0,3%, preferably ≤ 0.2% of Zr, ≤ 0,2%, preferably ≤ 0,1% Cu, ≤ 3% Zn, ≤ 0,2% In ≤ 0,1 Sn and ≤ 0.7%, and preferably ≤ 0,35%, (Fe+Ni), ≤ 1.0% and for soldering in an inert gas atmosphere with a flux ≤ 0,3%, most preferably ≤ 0.05% of Mg, and the rest - and Al ≤ 0.05% of each of the unavoidable impurities;

- providing a barrier layer of a second alloy which contains (in wt.%): ≤ 0,2% Mn+Cr, 1.6 to 5%, preferably 2-4,5% Si, ≤ 0,3%, preferably < 0,2% Ti, ≤ 0.2% of Zr, ≤ 0,2%, preferably ≤ 0,1% Cu, ≤ 3% Zn, ≤ 0,2% In ≤ 0.1% of Sn and ≤ 1,5%, preferably ≤ 0,7%, most preferably 0,1-0,35% (Fe+Ni), ≤ 1.0% and for soldering in an inert gas atmosphere with a flux ≤ 0,3%, most preferably ≤ 0.05% of Mg, and the rest - and Al ≤ 0.05% of each of the unavoidable impurities;

- the joint rolling layers so that they collided and formed a multilayer material;

- heat treatment of multilayer material at a predetermined temperature and for a predetermined time so that the Si content lined up to 0.4-1% in both the core layer and the barrier layer;

- rolling of multi-layer material to final thickness.

[0023] the Core layer has a high manganese content, which means that it has a high resistance to deformation, but due to the low content of silicon in this layer, the number of dispersoids little, and, thus, the deformation resistance during hot rolling is lower than in case of high content of silicon. The barrier layer has you�okoe silicon content, which means that its resistance to deformation is higher than with a low content of silicon, and the resistance to deformation of the core layer and barrier layer will, therefore, vary to a lesser extent, which significantly improves performance and contributes to the adhesion with the joint rolling. The content of magnesium in the core layer is lower than that in the barrier layer, resulting in further decrease the difference in the deformation resistance.

[0024] In the first stage, the core layer are rolled together with the barrier layer on one side or both sides, obtaining a multilayer material. This is advantageously carried out by hot rolling. The multilayered material can then be subjected to cold rolling. The degree of cold rolling is determined by the finite thickness of the multilayer material and the desired material properties. It is advisable to laminating multilayer material up until its thickness is 8-33% more than the final thickness, preferably 8-28% more than the final thickness, even better on 8-16% more than the final thickness, for best results.

[0025] the Multilayer material is then subjected to heat treatment at temperatures from 350°C to 500°C for sufficient time to perekristalizovanny and the silicon barrier layer from diff�was niraval in the medullary layer. This heat treatment is called hereinafter the term "intermediate annealing". The manganese in the core layer is released in a high degree in the form of small inhibiting the recrystallization of secretions Al-Si-Mn, the so-called dispersoids. The silicon content after the intermediate annealing should be at the level of 0.4-1% in both the core layer and barrier layer. The length of the intermediate annealing depends on the size of the material and temperature of the intermediate annealing, and preferably is from 1 to 24 hours. By maintaining the silicon content below 1% prevents the melting layer, and the minimum content of 0.4% means that, due to the formation of dispersoids, medullary layer not paracrystalline fully during the soldering material, which is most often carried out at a temperature 590-610°C. After the above-mentioned intermediate annealing the multi-layer material treated with pressure up to its final thickness by cold rolling. The final degree of pressure treatment depends on the desired material properties in the finished product and how badly the multilayer material was treated at the earlier stages. Advantageously, cold rolling is carried out with the degree of compression, component 8-33%, preferably 8-28%, and most preferably 8-16%, of the final thickness.

[0026] Since the core layer prior to rolling has a low content of silicon, and the barrier layer is a high content of silicon, the difference in deformation resistance during rolling is not that large, meaning that the performance will be rolling good. When then carry out intermediate annealing, the core layer will be formed a dense number of dispersoids, giving the desired inhibiting the recrystallization effect during soldering. If silicon is present in high content in the core layer, it will form a dense number of dispersoids, giving high resistance to deformation. Inhibits the recrystallization effect of dispersoids can still be obtained if dispersoid formed later in the process of the above-mentioned intermediate annealing.

[0027] the barrier layer paracrystalline, even if this layer is thin, because of its low content of manganese, zirconium and chromium mean that in the barrier layer is formed much less dispersoids. The desired amount of large grains in the barrier layer is achieved by maintaining the contents of iron and Nickel at a low level. Such material is particularly suitable for soldering to a surface that has been coated with solder. Thus, advantageously, there is no other layer of any kind on the PT�Ron barrier layer, looking from the core layer.

[0028] Since the deformation resistance of the medullary layer and barrier layer are not significantly different, the performance of the rolling is very good. The above multi-layer material provides a number of advantages after the aforementioned rolling and intermediate annealing; the barrier layer paracrystalline in large grain size when heated to soldering temperatures, the diffusion of silicon from the solder in the core is significantly reduced. Carefully selected compositions of the alloys in the core layer and barrier layer help to give the multilayer material of good strength properties at high temperature after soldering by combating the recrystallization of the core layer. So the material has high fatigue strength and good creep resistance at temperatures up to 300°C. After brazing clad material has a very good soldered seams.

[0029] the Multilayer material may consist of a core layer of a first aluminum alloy and a barrier layer of a second aluminum alloy, which is located on one side of the core layer.

[0030] the Multilayer material may consist of a core layer of a first aluminum alloy and two barrier layers of a second aluminum alloy�VA, located on each side of the core material.

[0031] Advantageously, the barrier layer is the outermost layer of the multilayer material on that side of the multilayer material, which must be soldered to another part. This material is very suitable as a thin sheet for use as fins in heat exchangers.

[0032] Advantageously, the barrier layer after the heating to the soldering temperature has a recrystallized structure with parallel surfaces rolling a grain size greater than 50 microns, which minimizes the penetration of silicon from the solder in the core that, in turn, contributes to a more robust solder joint.

[0033] the Core layer can have supercriticality or partially recrystallized structure after brazing. This structure core layer is essential to give a high strength multi-layer material.

[0034] Advantageously, the multilayer material after brazing is the fatigue strength, which is more than 35 MPa at 1 million cycles of loading with tensile load R=0,1 at 300°C.

[0035] Advantageously, the multilayer material satisfies the following conditions: 0,4%≤Cs∙x/100+Ck∙(100-x)/100≤1,0%, where Ck represents the percentage of the silicon in the core layer before rolling, Cs represents the FDS�th the percentage of silicon in the barrier layer before rolling, and x is the thickness of the barrier layer (or the total thickness of the barrier layers in the case of the two barrier layers) in % of the total thickness of the multilayer material after rolling. If these conditions are met, will be achieved at the desired inhibiting the recrystallization effect in the medullary layer and prevented the melting of this layer during soldering.

[0036] the Invention relates to a method for manufacturing a multi-layer material for brazing, which includes stages:

- providing a core layer of a first alloy, which contains (in wt.%): Of 0.5-2.0%, preferably of 0.8 to 1.8%, most preferably from 1.0 to 1.7% Mn, ≤0,2%, preferably ≤0,1% Si, ≤0.3% of Ti, ≤0,3%, preferably ≤0.2% of Cr, ≤0,3%, preferably ≤0.2% of Zr, ≤0,2%, preferably ≤0,1% Cu, ≤3% Zn, ≤0,2% In ≤0.1% of Sn and ≤0,7%, preferably ≤0,35%, (Fe+Ni), ≤1,0%, as for soldering in an inert gas atmosphere with a flux ≤0,3%, most preferably ≤0.05% of Mg, and the rest - and Al ≤0.05% of each of the unavoidable impurities;

- providing a barrier layer composed of a second alloy which contains (in wt.%): ≤0,2% Mn+Cr, 1.6 to 5%, preferably 2-4,5% Si, ≤0,3%, preferably < 0,2% Ti, ≤0.2% of Zr, ≤0,2%, preferably ≤ 0,1% Cu, ≤3% Zn, ≤0,2% In ≤0.1% of Sn and ≤1,5%, preferably ≤0,7%, most preferably 0,1-0,35% (Fe+Ni), ≤1.0% and for soldering in an inert gas atmosphere with a flux ≤0,3%, most preferably ≤0.05% of Mg, and the rest - and Al ≤0,05% �aidou inevitable impurities;

- the joint rolling layers so that they are bonded and formed a multilayer material;

- heat treatment of multilayer material at a predetermined temperature and for a predetermined time so that the Si content lined up to 0.4-1% in both the core layer and the barrier layer;

- rolling of multi-layer material to final thickness.

[0037] the Multilayer material can be rolled into sheets or plates of different lengths with a low deviation in thickness on the surface of the sheet. Since the difference in deformation resistance between the core layer and the barrier layer is small, this method, accordingly, provides a safe and efficient manufacture of laminated material with high performance and high output.

[0038] Prior to hot rolling may be located on another layer of the second aluminum alloy on the other surface of the core layer so that the core layer was surrounded by a barrier layer on both sides. Thus fabricated multi-layered material that can be soldered on both sides.

[0039] On the other surface of the core layer can be located more layers of aluminum alloy, which has special properties corrosion protection, so that the core layer was surrounded by a bar�Arnim layer on one side and protects against corrosion layer on the other side.

[0040] the Joint rolling layers is advantageously carried out by hot rolling at 350°C-500°C.

[0041] Then, the multilayer material is subjected to cold rolling. The degree of cold rolling selected based on the desired final thickness and desirable properties in the finished product. Advantageously, the multilayer material is rolled until then, until it becomes in 8-33% thicker than the final thickness, preferably on 8-28% thicker than the final thickness, particularly preferably 8-16% thicker than the final thickness, for best results.

[0042] At the next stage multilayer laminated material is subjected to heat treatment at a high temperature, 300°C-500°C. the Temperature is preferably 350°C-500°C, and the period of time during which the material is heated depends on the material and concrete temperature. Advantageously, the material is heated for a time from 1 to 24 hours. Through heat treatment, so-called intermediate annealing, the internal structure of the multilayer material is changed so that the entire layer is recrystallized, the diffusion of silicon from the barrier layer in the core layer leads to the release of manganese in the form of numerous selections Al-Mn-Si, and the content of silicon in the barrier layer is reduced to 1% or below.

[0043] Finally, the multi-stakeholder�oiny the material undergoes additional cold pressure treatment, usually by cold rolling to final thickness. The final degree of pressure treatment depends on the desired material properties of the final product and how badly the multilayer material was treated at the earlier stages. Advantageously, the multi-layer material treated with pressure up to final thickness with the degree of compression 8-33%, preferably 8-28%, most preferably 8-16%, of the final thickness. During the cold forming internal structure of the material changes, and its strength increases. This increase in strength is partially retained by the material and brazed heat exchanger, since the core layer is not paracrystalline fully during soldering. This is because the driving force for recrystallization is low due to the low degree of reduction during cold working pressure after the intermediate annealing, and the fact that inhibiting recrystallization force is high due to numerous allocations of the Al-Mn-Si. Low degree of compression during cold working pressure also allows you to increase the size of the grains in the barrier layer, when it paracrystalline when heated to soldering temperatures. This prevents the penetration of silicon from the solder and the melting of the barrier layer and core layer.

[0044] the barrier layer, the thickness of which SOS�ulation of 7 μm or more, provides excellent resistance to the penetration of silicon from the material of the solder, if the rate of heating during soldering is at least 25°C/min.

[0045] the Invention also relates to a method of manufacturing a brazed product, comprising the above described multilayer material, where the barrier layer has a recrystallized structure with a grain size with the length parallel to the rolling surface, which is at least 50 μm. Recrystallized, coarse-grained structure in the barrier layer created during heating to the soldering temperature, causes less diffusion of silicon from the solder in the core, resulting in a more durable brazed seam and reduces the risk of partial melting of the barrier and core layers of the multilayer material during soldering. Because the core layer is not paracrystalline and contains numerous fully discharge, obtained brazed product in which the multilayer material contributes to high strength and very good creep properties, and fatigue, especially at high temperatures up to 300°C inclusive. Multilayer material and brazed product contains medullary layer of deformed, supercriticality or partially recrystallized structure, and a multilayer material has a yield strength Rp0,2 at least 60 MPa at room temperature. Multilayer material in this product has good corrosion resistance, due to the fact that the multilayer material has a core layer that is more noble than the barrier layer, and a barrier layer, which contains little of the intermetallic particles.

[0046] the Brazed product suitable manner is a heat exchanger.

[0047] the Invention also relates to the application of brazed products with temperatures reaching in excess of 150°C or above 200°C or above 250°C. This product is particularly suitable for such applications because it has very good strength properties at high temperatures.

[0048] the Brazed product is also particularly suitable in heat exchangers with working temperatures below 100°C because of high strength, which material has at these temperatures, means that the material in the product can be thinner, which leads to a cheaper product with less mass. The smaller mass is particularly advantageous in the case where the product is used in motor vehicles, because then it reduces the fuel consumption of the vehicle.

Detailed description of the invention

[0049] the inventors have discovered a method of manufacturing a multi-layer material dlatego of brazing sheet for heat exchangers, which has a very high strength in comparison with existing materials, even at high temperature, and very good corrosion properties, and can be manufactured with high productivity and high yield.

[0050] Since the barrier layer in thin sheets, such as sheets of fins in heat exchangers, should have a thickness equal to at least about 7 microns to provide the desired protective function, and therefore it is a significant part of the thickness of the multilayer material, the problem of poor performance in the rolling process is particularly severe in this case. But the required thickness depends on the temperature/duration of the cycle during brazing. For a long time at high temperature is required, a thicker barrier layer.

[0051] the Experiments on the rolling layers of different hardness showed that the productivity of the hot rolling is significantly improved, if the hardness of the layers during hot rolling in the temperature range 350-500°C do not differ too much.

[0052] the adhesion between the layers during hot rolling is greatly simplified if the maximum deformation resistance of the barrier layer during hot rolling in the temperature range 350-500°C does not differ too greatly from the maximum resistance strain�Yu of the core material. Butoxide aluminum surface is very quickly covered with oxide when it comes into contact with air. Thus, to achieve the clutch during the rolling process must be created on the metal surface without oxide as the core layer and the barrier layer so as to achieve a contact of metal to metal between the layers during the rolling process. If the barrier layer and the core layer have approximately the same resistance to deformation, their surface will be stretched to approximately the same degree during rolling. This ensures the contact of the metals between the surfaces at any time and provides a good grip between them.

[0053] the barrier layer can be made solid by quenching in a solid solution if it is possible to use a higher content of alloying materials, such as magnesium or copper, which can be maintained in solution. Under certain types of soldering, such as soldering in an inert gas with flux, it is impossible to achieve good soldering properties, if the magnesium content is too high. The high content of copper cannot be used in the fin sheet which is brazed to the tubes, since it gives the highest electric potential, leading to enhanced corrosion of pipes. Another way is the introduction of alloying substances that clicks�form particles. This is less preferable, because the barrier layer is designed to recrystallization in large grains when heated to soldering temperatures, before the diffusion rate of silicon becomes high, despite the fact that it is thin, and the driving force for recrystallization is low.

[0054] Thus, one problem is to find the composition for the barrier layer, which provides a sufficiently high deformation resistance during hot rolling and also leads to material that paracrystalline in large grain size when heated to soldering temperatures. The experiments showed that the smaller the size of the grains in the barrier layer and the thinner the barrier layer, the harder it is to prevent the penetration of silicon from the solder material in the core. Thus, the choice of alloying materials in the barrier layer is very limited, taking into account the production capacity of rolling and recrystallization properties. The thickness of the required barrier layer for recrystallization and provide the necessary protection against the penetration of silicon, depends on the rate of heating during soldering.

[0055] In the present invention, the content of silicon in the barrier layer is high during the rolling process, which creates numerous particles and a lot of silica in solution, which is p�idet high resistance to deformation. The silicon content in the alloy of the core is low during the rolling process that produces fewer particles and thus less resistance to deformation. The barrier layer should precrystallization prior to hot rolling by heating to soldering temperature. The minimum thickness of the barrier layer is chosen based on its desired function and the rates of heating during soldering. The high density of particles required in the core layer to perekristalizovanny during soldering, introduced during the aforementioned intermediate annealing before final rolling. During this annealing, the silicon content in the barrier layer decreases, which means that it does not melt during brazing, and corrosion properties significantly improved in that the alloy composition becomes more similar to pure aluminum.

[0056] In the multilayered material according to the invention the alloy of the core after the intermediate annealing before rolling to final size contains a large number of particles per unit volume, which creates a greater retarding force against recrystallization and very high resistance to fatigue and creep at high temperature.

[0057] As can be seen, it is important to choose the alloying material and balance the content of alloying material in the core layer and barrier �Loewe thus, to obtain a multilayered material that has good strength properties at high temperatures and can be processed by rolling with high productivity and good yield. Then follows the description of the effect of individual alloying elements in multilayer material.

[0058] the Silicon contributes to the resistance to deformation, especially at high strain rates. The silicon content in the core layer before the intermediate annealing, which are used to align the silicon content in the core and barrier layers must be ≤0,2, preferably ≤ 0.1 wt.%. The content of silicon in the barrier layer must be sufficiently high to give it the deformation resistance during hot rolling, equal to the resistance to deformation in the core layer, and promote the excretion of manganese in numerous particles in the core layer during the intermediate annealing before rolling to final thickness. But the silicon content should not be so high that the core layer and a barrier layer is melted during soldering. Preferably, the silicon content in the barrier layer before heat treatment, designed to align the silicon content between the core and barrier layers must be at 1.6-5.0 wt.%. Alsoabout�about, the content of silicon in the barrier layer is 2.0-4.5 wt.%.

[0059] Magnesium increases the strength of the material by quenching in a solid solution, if present in solid solution, or by the formation of secretions Mg2Si during aging. In addition, the magnesium increases the deformation resistance during rolling at high temperature, which means that its use mainly in the barrier layer. If its content is excessively high, the ability to ration decreases due to the formation of a thick layer of magnesium oxide on the surface, and, in addition, there is a risk of melting of the material at the temperature of brazing, which forces us to restrict the content of magnesium in the core layer to 1.0 wt.%. During soldering in an inert gas with flux magnesium reacts with the flux, which reduces the ability to braze. The ability to solder decreases with increasing content of magnesium. Magnesium in the core layer diffuses in the barrier layer during heat treatment and brazing. The content of magnesium in the core layer is therefore limited to 0.3 wt.%, preferably 0.05 wt.%, if the material is intended for use when soldering in an inert gas with flux.

[0060] In the barrier layer, for the same reason as in the medullary layer, the magnesium content is usually limited to 1.0 wt.%. When the most common size� currently the method of soldering - soldering in an inert gas with a flux - barrier layer should not have a magnesium content higher than about 0.3 wt.%, because magnesium has a negative impact on the function of the flux. The magnesium content in the barrier layer must therefore be ≤ 0.3 wt.%, preferably ≤ 0.05 wt.%, if the material is intended for use when soldering in an inert gas with flux. Is it possible to allow a higher magnesium content than 0.3 wt.%, if the material is suitable for vacuum brazing.

[0061] Zinc is used for reducing the electric potential of the material, and it is very often used to provide cathodic protection of tubes in the heat exchanger. In the core and barrier layers can be used up to 3% Zn.

[0062] the Zirconium increases the bending strength and provides increased resistance to recrystallization. Up to 0.3 wt.% zirconium can be introduced into the composition of the core layer. Zirconium is distributed mainly in the form of small particles of Al3Zr, and these particles inhibit recrystallization and form large grains in the material after brazing. As the particles of Al3Zr are stable even at very high temperatures exceeding 300°C, they increase the resistance to fatigue and creep at high temperatures. Above 0.3 wt.% form large discharge, which is negative in�EUT on the formability of the material. Preferably, the content of Zr in the core layer is limited to 0.2 wt.%. As Zr increases the resistance to deformation, the choice of Zr content in the core layer represents a compromise between the negative effect of the increased resistance to deformation during rolling and positive effects of increased inhibition of recrystallization during brazing and increased strength of brazed products. The content of the zirconium barrier layer should not exceed 0.2 wt.%, because it can't be higher level, which allows recrystallization of the barrier layer during soldering and provides desirable protection against the introduction of silicon.

[0063] the Titanium increases the strength and may be present in the medullary layer up to 0.3 wt.%. In a barrier layer of titanium may be present up to 0.3 wt.%, preferably ≤ 0.2 wt.%. Because these grades titanium does not form a discharge, which can delay the process of recrystallization, it can be used to improve the resistance to deformation of the barrier layer during rolling at high temperature.

[0064] the Manganese in solid solution increases strength, bending strength and corrosion resistance. Manganese in the discharge increases strength. When a suitable heat treatment at those�the peratures below 500°C the manganese forms small particles, the so-called dispersoid, with an average diameter of less than 0.5 μm, which increases the bending strength, inhibits recrystallization during brazing and increases the strength at low and high temperatures. The manganese content in the core layer should be 0.5 to 2.0%, preferably of 0.8 to 1.8%, most preferably from 1.0 to 1.7%. In the barrier layer, the content of manganese + chromium should not exceed 0.2 wt.%, since the barrier layer should precrystallization at soldering temperatures.

[0065] the Iron and Nickel have a negative effect on the corrosion resistance and even more on the bending strength, the introduction of silicon from the solder and the core layer by recrystallization. This is because iron and Nickel form a large discharge, which serve as nuclei for recrystallization, which reduces the size of the grains. Therefore, the content of Fe+Ni in the core layer should be limited to 0.7 wt.%, preferably up to 0.35 wt.% in the medullary layer. Their content in the barrier layer is limited to 1.5 wt.%, but preferably should be below 0.7 wt.%. Advantageously, the content in the barrier layer is 0.10 to 0.35 wt.%.

[0066] the Copper at higher content than 0.2 wt.%, has a drawback consisting in that the barrier layer can be more noble than the tube and in other�important part of the coil, what, from the point of view of corrosion, causes unwanted gradient of the electric potential. Therefore, the copper content of the core and the barrier layer should not exceed 0.2 wt.%, preferably not exceed 0.1 wt.%.

[0067] Chromium, zirconium and manganese, is a so-called dispersonalisation at low contents. As a higher chromium content form large particles, the chromium content in the core layer should not exceed 0.3 wt.%. The sum of the contents of manganese and chromium in the barrier layer should not exceed 0.2 wt.%, since the barrier layer should precrystallization at soldering temperatures.

[0068] indium and tin are sometimes added in small quantities to modify the electrochemical nature of the material. Their content should be limited to ≤ 0.2% for India and ≤ 0.1% for tin.

The drawing list

[0069] Fig.1 shows the content of silicon and manganese as a function of depth from the surface of the plate to the middle of it multilayer material according to the invention with a core alloy 1 and alloy 2 barrier layer of example 1 after the intermediate annealing and rolling to 0.07 mm. the Concentration of silicon and manganese were measured by the method of energy dispersive spectroscopy in a scanning electron microscope, the points at different depths in longitudinal section of a multilayer� plate. Large deviation in composition from one point to another due to the fact that the bulk of the silicon in the core layer is in the selections.

Fig.2 shows the microstructure in longitudinal section after simulating brazing heat treatment in the border area between the barrier layer (lower part) and the core layer in multilayer material according to the invention with a core alloy 1 and alloy 2 barrier layer of example 1.

Fig.3 shows the microstructure in the section through the seam formed in the case where a multilayer material according to the invention with an alloy 1 core and 10% of the thickness of the barrier layer 2 on each side formed in the so-called edge and soldered to the tube of laminated material consisting of Al-Mn-nd alloy with an intermediate layer of pure aluminum and a layer of solder made of aluminum alloy with 10% Si. Multilayer material was rolled with a reduction corresponding to 16% of the initial thickness, an intermediate annealing and soldering.

Fig.4 shows the image of a multilayer material according to the invention, obtained by scanning electron microscope in the so-called "back scattering". This image shows the grain structure in longitudinal section after simulating brazing heat treatment. Multilayer material consisted of alloy 1 core with 10% thickness�s barrier layer 2 on each side. It was rolled with a reduction corresponding to 16% of the initial thickness, an intermediate annealing and soldering. As this figure shows, the alloy of the core has deformed structure, while the barrier layer was perekristalizovanny in large grain size.

Fig.5 shows a comparison of the strength changes depending on the temperature for the layered material of example 2 and the strength of the standard alloy for edges.

Fig.6 shows the comparison of the change in the fatigue strength depending on the temperature for the multilayer material according to the invention of example 2 and the corresponding properties of the standard alloy for edges.

Fig.7 shows the comparison of the change in creep resistance depending on the temperature for the multilayer material according to the invention of example 2 and the corresponding properties of the standard alloy for edges.

Examples

[0070] the Following examples describe the results of experiments conducted with a multi-layer material according to the invention, compared with the standard material.

Example 1

[0071] a Multilayer material according to the invention is produced by connecting together plates of alloys of the barrier layer and plate alloy core layer by rolling. The compositions of the various layers are presented in table 1. Serdtsevinnye supplied plates of the barrier layer on each side, moreover, the barrier layer on each side were 10%, 15% or 20% of the total thickness. The first layer was heated to 480°C for 2 hours. Rolling was carried out without problems of adhesion. The deviation of the thickness on the surface of the plates was less than 1%. Then, the laminate was rolled up until the thickness was 0.09 mm. Laminated plates subjected to soft annealing so that they are fully precrystallization and the silicon content was on average similar in the core and barrier layers, see Fig.1. After this laminate was rolled to different reductions in thickness from 5% to 25% of the initial thickness.

Table 1
The composition of alloys
SiFeMnOther
Alloy 1 core0,090,151,6<0.01
Alloy 2 core0,080,161,1<0.01
Alloy 3 core0,090,150,6<0.01
The barrier layer 12,00,17<0.01<0.01
The barrier layer 24,20,17<0.01<0.01

[0072] the Blank of laminated material hung vertically in an oven with an atmosphere of gaseous nitrogen and subjected to heat treatment similar to that used for brazing of automotive radiators: heating from room temperature to 600°C for 20 minutes, then soak for 3 minutes at this temperature, followed by rapid cooling to room temperature. The barrier layer was perekristalizovanny in all cases in grains larger than 50 μm, before the temperature reached 550°C. Cm. the example in Fig.4.

[0073] the Strength of multi-layer material depends on the degree of compression prior to modeling the soldering. Table 2 gives some examples.

Table 2
The yield strength p0,2for multi-layer material with a thickness of 0.06-0,085 mm after soldering modeling. Compression during rolling is expressed in % of the thickness before rolling
Compression during rolling before soldering (%)Rp0,2(MPa)
Core 1+20% of the barrier layer 1740
1250
1762
2538
Core 1+10% of the barrier layer 2542
1054
1871
2540
Core 2+10% of the barrier layer 2642
1155
1673
2435
CE�Davina 3+10% of the barrier layer 2 548
1058
1663
2042
2535

[0074] yield strength, Rp0,2for certain combinations after soldering modeling is as much as 60-70 MPa at room temperature, which should be compared to 40 MPa at standard alloys for solder in an inert gas of heat exchangers, such as EN-AW 3003. The reason is that during the annealing of a dense number of dispersoids, see Fig.2 that along with the low degree of deformation during the rolling process to allow the core material to save partially deformed structure.

[0075] the Multilayered material was soldered in an inert gas after plusovaya coated with solder to the tube thickness of 0.40 mm. brazing joints between the multilayer material and the tube showed good filling, if the degree of compression during rolling before soldering totaled at least 8%. An example of a brazed seam shown in Fig.3.

Example 2

[0076] a Multilayer material according to the invention were subjected to the same simulation brazing heat treatment as in example 1. Table 3 show�for the composition of the alloys after heat treatment. It is compared with a standard material EN-AW 3003, for ribs in automobile radiators. The standard material was subjected to the same simulation brazing heat treatment, and a multilayer material, and its composition is also presented in table 3. Fig.5 shows the change of static strength depending on the testing temperature. Fig.6 and 7 illustrate the fatigue strength and creep resistance, respectively, at different temperatures. These figures show that the multi-layered material has superior properties compared with a standard material at room temperature and elevated temperature in relation to the static strength, including fatigue strength, and creep resistance.

Table 3
The composition of the alloys after modeling
brazing heat treatment, wt.%
SiFeCuMnMgZrTiOther elements, each
Multilayer material
Alloy �of ardavin
The barrier layer
0,50,3<0,021,60,20,10,04<0,02
0,10,3<0,02<0,020,2<0,020,1<0,02
Standard material EN-AW 30030,10,50,11,2<0,02<0,02<0,02<0,02

Example 3

[0077] the deformation Resistance was measured for several different alloys according to table 4. Samples were selected from the alloy ingot was subjected to heat treatment at 500°C for 8 hours. The deformation resistance was measured as the maximum force per unit cross-sectional area required for the deformation of cylinders with a height of 21 mm and a diameter of 14 mm. At each end of the cylinders were cut a round groove depth of 0.2 mm and a width of 0.75 mm at distance�and 2 mm from each other. The cylinders are heated to the test temperature and deformed at strain rate of 2-1to at least 50% reduction in height. The lubricant used boron nitride.

[0078] the Results of deformation at 480°C are presented in table 4.

Table 4
The deformation resistance at 480°C
AlloyThe deformation resistance at 480°C (MPa)
Al-0,2% Fe-0.1% of Si25
Al-0,2% Fe-4%Si32
Al-0,2% Fe-1.5% of Mn-0,07%Si40
Al-0,2% Fe-1,5% Mn-0.8% of Si70

[0079] As shown in table 4, the deformation resistance of the alloy Al-0,2% Fe-0.1% of Si is only 36% of the resistance to deformation of the alloy Al-0,2% Fe-1,5% Mn-0.8% of Si. With increasing silicon content up to 4% in the first specified alloy and reducing the silicon content to 0.07% in the second alloy, the ratio of the resistance to deformation increases to 80%, which should significantly contribute to the adhesion and to improve performance during rolling at 480°C. Thus, by the heat�coy processing at high temperature multilayer material according to the invention with a core layer of Al and 0.2% Fe-1.5% of Mn-0,07%Si and the barrier layer Al and 0.2% Fe-4%Si, you can cause the silicon to diffuse from the barrier layer in the core layer, so that the alloy in the core will be similar to the alloy Al-0,2% Fe-1,5% Mn-0.8% of Si and the alloy in the barrier layer will be similar to the alloy Al-0,2% Fe-0.8% of Si, which should give desirable properties in relation to inhibition of recrystallization in the core layer and the effect of barrier layers and good corrosion resistance in the barrier layer.

1. A method of manufacturing a multilayer material for brazing, comprising the following stages:
- providing a core layer of a first aluminum alloy, which contains, wt.%:
Mn: 0.5 to 2.0 percent, preferably 0,8-1,8%, most preferably from 1.0 to 1.7%
Mg: ≤1,0%, preferably ≤ 0,3%, most preferably ≤0,05%
Si: ≤0,2%, preferably ≤0,1%
Ti: ≤0,3%
Cr: ≤0,3%, preferably ≤0,2%
Zr: ≤0,3%, preferably ≤0,2%
Cu: ≤0,2%, preferably ≤0,1%
Zn: ≤3%
In: ≤0,2%
Sn: ≤0,1%
Fe+Ni: ≤0,7%, preferably ≤0,35%
the rest - and Al ≤0.05% of each of the unavoidable impurities;
- providing a barrier layer of a second aluminum alloy on at least one side of the core, and the second aluminum alloy contains, wt.%:
Mn+Cr: ≤0,2%
Mg: ≤1,0%, preferably ≤0,3%, most preferably ≤0,05%
Si: 1.6 to 5%, preferably 2-4,5%
Ti: ≤0,3%, preferably <0,2%
Zr: ≤0,2%
Cu: ≤0,2%, preferably ≤0,1%
Zn: ≤3%
In: ≤0,2%
Sn: ≤0,1%
(Fe+Ni): ≤1,5%, preferably ≤0,7%, preferably 0,1-0,3%
the rest - and Al ≤0.05% of each of the unavoidable impurities;
- the joint rolling layers so that they mated with the formation of multi-layer material;
- heat treatment of multilayer material at a temperature from 300 °C to 550 °C for a predetermined time so that the Si content lined up to 0.4-1% in both the core layer and the barrier layer;
- rolling laminated material prior to final thickness with the degree of compression from 8% to 33%.

2. A method according to claim 1, wherein the multilayered material before heat treatment is also subjected to cold rolling to until a multilayer material becomes 8%-33% thicker than the intended final thickness, preferably 8%-28% thicker than the intended final thickness, most preferably 8%-16% thicker than the intended final thickness.

3. A method according to claim 1 or 2, wherein the multilayered material after heat treatment is subjected to cold rolling to final thickness with the degree of compression from 8% to 33%, preferably from 8% to 28% from the intended final thickness.

4. A method according to claim 1 or 2, wherein the heat treatment is carried out at a temperature between 350°C and 550°C.

5. A method according to claim 3, wherein the heat treatment is carried out at a temperature between 350°C and 550°C.

6. A method according to claim 1 or 2, wherein the heat treatment is carried�tlaut for a time of 1-24 hours.

7. A method according to claim 3, in which heat treatment is performed for a time of 1-24 hours.

8. A method according to claim 4, wherein the heat treatment is performed for a time of 1-24 hours.

9. A method according to claim 1 or 2, including the step of providing a core layer of a first aluminum alloy and two barrier layers of a second aluminum layer, wherein the barrier layer is located on each side of the core material.

10. A method according to claim 3 comprising the step of providing a core layer of a first aluminum alloy and two barrier layers of a second aluminum layer, wherein the barrier layer is located on each side of the core material.

11. A method according to claim 4, comprising the step of providing a core layer of a first aluminum alloy and two barrier layers of a second aluminum layer, wherein the barrier layer is located on each side of the core material.

12. A method according to claim 6, comprising the step of providing a core layer of a first aluminum alloy and two barrier layers of a second aluminum layer, wherein the barrier layer is located on each side of the core material.

13. A method according to claim 1 or 2, wherein the barrier layer or layers form the outermost layer of the multilayer material on that side of the multilayer material, which must be soldered to another �Italy.

14. A method according to claim 3, wherein the barrier layer or layers form the outermost layer of the multilayer material on that side of the multilayer material, which must be soldered to another part.

15. A method according to claim 4, wherein the barrier layer or layers form the outermost layer of the multilayer material on that side of the multilayer material, which must be soldered to another part.

16. A method according to claim 6, wherein the barrier layer or layers form the outermost layer of the multilayer material on that side of the multilayer material, which must be soldered to another part.

17. A method according to claim 1 or 2, wherein the content of silicon in the layers satisfies the condition of 0.4% ≤Cs∙x/100+Ck∙(100-x)/100 ≤1,0%, where Ck is a silicon content in the core layer before rolling, Cs is the silicon content in the barrier layer before rolling, and x is the thickness of the barrier layer or, in the case of two barrier layers, the total thickness of the barrier layers in % of the total thickness of the multilayer material after the joint rolling.

18. A method according to claim 17, wherein x is 7 μm or more.

19. Clad brazing material, manufactured by the method according to any one of claims. 1-18.

20. A method of manufacturing a brazed products, including high temperature brazing of megolo�tion material according to claim 19 for details.

21. A method according to claim 20, in which the barrier layer to give precrystallization during brazing so that it has the grain size with the length parallel to the rolling surface of the multilayer material, which is at least 50 microns.

22. A method according to claim 20 or 21, in which the core layer of the multilayer material has supercriticality or partially recrystallized structure after brazing.

23. A method according to claim 20 or 21, in which the multilayer material after high-temperature brazing has a yield strength that is at least 60 MPa at room temperature.

24. A method according to claim 20 or 21, in which the multilayer material after high-temperature brazing has a fatigue strength greater than 35 MPa for one million cycles of loading with tensile load R=0,1 at 300°C.



 

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Aluminium alloy // 2536566

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4 cl, 3 tbl

FIELD: metallurgy.

SUBSTANCE: invention relates to an extruded or rolled clad metal product and can be used in the transport industry, aerospace products and ships. The product includes a cladded metal layer and a cladding metal layer on at least one surface of the cladded layer; with that, the cladded and the cladding metal layers are made from aluminium alloys containing the following, wt %: 3 to 8 Mg and Sc in the range of 0.05 to 1; with that, the content of Sc in the alloy of the cladded layer is lower than its content in the alloy of the cladding layer by 0.02% or more. The invention also relates to a welded structure including such a metal product.

EFFECT: as a result of use of the invention, products are made from the aluminium alloy containing Sc with an improved strength and weldability balance.

14 cl, 1 ex

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy, particularly to production of light materials with low linear expansion factor and can be used as a structural material in production of aircraft control system high-performance controllers. Proposed composition contains the following substances, in wt %: silicon - 41-45, nickel - 3.9-5.6, iron - ≤0.48, aluminium oxide ≤2.8, aluminium making the rest. Proposed process comprises silicon powder grinding to required dispersity, magnetic separation of silicon powder, mixing of the latter with powder of aluminium alloy "CAC1-50", filling of produced mix in capsule, vacuum degassing, gas-static compaction of capsules and removal of aluminium shell.

EFFECT: nontoxic material that features stable-size, low specific weight, good machinability, low linear expansion factor, low magnetic susceptibility.

2 cl, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to components processed by precision turning, said components being obtained from extruded products of the rod, bar or even tube type made from a deformable aluminium alloy for precision turning. The alloy has the following composition, wt %: 0.8<Si<1.5, preferably 1.0≤Si<1.5; 1.0<Fe<1.8, preferably 1.0<Fe≤1.5; Cu <0.1; Mn <1, preferably <0.6; Mg 0.6-1,2, preferably 0.6-0.9; Ni <3.0%, preferably 1.0-2.0; Cr <0.25%; Ti <0.1%; other elements <0.05 each and 0.15 in total, aluminium - the balance. The subject of the invention is also a component made by precision turning of such an extruded product as defined above.

EFFECT: invention is aimed at improving cutting ability of aluminium-based alloys containing not more than 1,5% silicon.

7 cl, 3 ex, 3 tbl, 3 dwg

Powder composite // 2509817

FIELD: metallurgy.

SUBSTANCE: invention can be used as a structural material for parts operated at high mechanical and thermal loads, for example, pistons of augmented ICEs operated at 350°C and higher. Proposed composition contains the following substances, in wt %: silicon - 12.05…14.65, nickel - 2.80…3.40, iron - 1.50…1.70, aluminium oxide - 1.05…1.30, carbon - 1.35…1.65, aluminium making the rest.

EFFECT: lower thermal expansion factor, higher heat and wear resistance.

4 dwg, 3 tbl

FIELD: electricity.

SUBSTANCE: invention refers to active material of negative electrode for electric device containing an alloy with composition formula SixZnyAlz, where each of x, y and z is mass percentage meeting the following: (1) x+y+z=100, (2) 26≤x≤47, (3) 18≤y≤44 and (4) 22≤z≤46. Also invention refers to electrical device and negative electrode for it.

EFFECT: providing active material of negative electrode for electrical device such as lithium-ion accumulator battery providing well-balanced properties of high cycling conservation and high initial capacity.

4 cl, 2 tbl, 10 dwg, 2 ex

FIELD: metallurgy.

SUBSTANCE: method for obtaining material in the form of a cast section involves preparation of aluminium melt containing 1-2 wt % of iron and 0.2 - 0.6 wt % of silicon, introduction to the melt at the temperature of 900-1100°°C of boron in the form of boric acid and titanium in the form of chips in the ratio allowing to obtain in cast structure of titanium diboride particles in the amount of 4 to 8 wt %, and crystallisation by casting to a mould.

EFFECT: obtaining boron-containing composite material on aluminium basis, which has high level of absorption of neutron emission in combination with the best mechanical properties and processibility.

5 ex, 2 tbl, 1 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to production of articles from aluminium alloys, particularly, to production of aluminium foil to be used as domestic foil, packing material, etc. this foil of produced by moulding of 6mm-deep strip, rolling it as-heated without mod annealing to depth smaller than 1 mm and further annealing. Note here that said aluminium alloy is aluminium alloy of series 1xxx, 3xxx or 8xxx. Aluminium alloy results from this processing that has no intermetallic beta-phase particles. Note here that this foil features depth of 5-150 mcm and structure, in fact, has no pores caused by axial liquidation of intermetallic particles.

EFFECT: higher tenacity, elongation and Mullen pressure after complete annealing.

2 cl, 4 dwg, 2 tbl, 2 ex

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