The base alloy of magnesium and how it will be handled in liquid, semisolid and solid states to obtain products with a homogeneous fine-grained structure

 

The invention relates to ferrous metallurgy, in particular the production of alloys based on magnesium, and methods for their processing. Alloys based on magnesium are used as a structural material in the manufacture of castings, products and deformed semi-finished products for applications in the automotive, aviation, space, electronic and other industries. The proposed alloy contains the following components, wt.%: zinc of 0.1-30, light rare earth metals (LRSM) 0,05-1,0, manganese 0,001-0,5, aluminum 0,001-0,1, iron is 0.0001 to 0.05, the silicon of 0.0001 to 0.05, magnesium else. A method for processing the claimed alloy comprising preparing a mixture, the preparation of the melt, the introduction of alloys of magnesium, manganese, magnesium, zirconium, magnesium, yttrium and magnesium-LRSM, melt refining, its maturation and subsequent casting. Before the introduction of the molten alloy is heated to a temperature of 20-50oWith lower temperature non-equilibrium solidus corresponding ligature, ligature magnesium-LRSM and magnesium-yttrium injected into the melt for 30 to 60 minutes before the start of the casting process. The technical result of the invention is to improve the ductility, impact zacosta, processability during deformation. 2 C. and 14 C.of alloys based on magnesium and methods of their processing. Alloys based on magnesium are used as a structural material in the manufacture of castings, products and deformed semi-finished products for applications in the automotive, aviation, space, electronic and other industries.

Known alloys based on magnesium-containing zinc, zirconium, rare earth metals.

These include alloys MA, MA, ML, ML-10, ML ("Magnesium alloys". The Handbook. So 1, 2. - M.: Metallurgizdat, 1978).

The disadvantage of these alloys is the heterogeneity of their grain structure, which causes instability and anisotropy of their physical, mechanical, technological and service properties. In addition, these alloys have low strength properties at temperatures above 100 to 150oWith that restricts their use. Applied methods of processing these alloys are as follows: preparation and heating of the charge materials, melting and casting of alloys, heat treatment of ingots and castings, hot forming, pressing, forging, pressing, stamping and so on, the final heat treatment of products. However, the technological parameters of processing of magnesium alloys used in practice (temperature of heating ingots and semi-finished products, speed Def the men.

Closest to the proposed alloy composition of ingredients and the method of its processing for the manufacture of ingots and all kinds of deformed semi-finished products are alloy MA (GOST 14957, Russia), having the following composition, wt.%: Zinc - 2,5-3,5 Zirconia - 0,45-0,90 Cadmium - 1,2-2,0 Lanthanum - 0,7-1,1 Magnesium Rest of This alloy, in addition to the above disadvantages similar to the alloys characteristic of this alloy contains a toxic element cadmium, the use of which is banned in many countries. In addition, the alloy contains as an alloying agent - lanthanum, which is expensive and scarce metal in comparison with mixtures of light rare earths (LRSM) and Ismatulla (MM).

A known technology for manufacturing alloy MA includes the steps: preparation of the charge materials, melting and casting of ingots, hot deformation of the ingot. However, the used method of obtaining and processing of the alloy MA does not guarantee obtaining a fine-grained structure and the desired level of properties, since it does not use homogeneously heat treatment of the ingot, the regulation of speed of deformation parameters and the final heat treatment products (Bondarev B. I. Smelting and casting of wrought magnesium alloy, containing as the basis magnesium, and zinc, and light rare earth metal and receiving ultra-light (j=a 1.75-1.8 g/cm3) a structural material in the form of ingots, castings, deformed semi-finished products and products with regulated homogeneous fine-grained structure with a controlled content of fine selections of primary and secondary hardening phases, uniformly distributed over the volume of the grains of the magnesium solid solution without the formation of a continuous skeleton of intermetallics on their borders.

This object is achieved in that the alloy contains, in weight%: Zinc - 0,1-3,0 Light rare earths (LRSM) (one or several elements of this subgroup cerium, lanthanum, neodymium, praseodymium) - 0,05-1,0
Manganese - 0,001-0,5
Aluminum - 0,001-0,1
Iron is 0.0001 to 0.05
Silicon is 0.0001 to 0.05
Magnesium - Rest
In the alloy impose additional modifier in the form of one of the additives, zirconium, calcium, strontium, in an amount of 0.01 to 1.0%.

As LRSM use their mixture in the form of mischmetall (MM) or Didymium (D), MM contains 55% cerium, 25% lanthanum, 15% neodymium, 5% praseodymium, and D contains 85% of neodymium, 15% praseodymium.

The alloy additionally contains from 0.5 to 5 wt.% yttrium. When casting alloy it is the use of manganese and aluminum respectively less than 0.1 and 0.02 wt.%.

The alloying components are designed in the following amounts, wt.%:
Zinc - 0,1-2,0
LRSM (MM) - 0,05-0,2
Zirconia - 0,05-0,3
Yttrium - 0,01-0,5
Manganese - 0,001-0,1
Aluminum - 0,001-0,02
Iron is 0.0001-0.01 to
Silicon is 0.0001-0,005
Magnesium - Rest
The zinc content in the alloy should be closer to the lower limit (0.1 to 1.0%), and the content LRSM (MM), yttrium and zirconium - closer to the upper limit.

The content of zinc, LRSM (MM), yttrium and zirconium - closer to the upper limit.

The content of zinc, LRSM (MM), yttrium, zirconium or manganese - closer to the upper limit.

When processing the alloy ligatures: magnesium-LRSM (MM), magnesium-yttrium, magnesium, zirconium, magnesium, manganese, before introducing them into the melt is heated to a temperature of 20-50oWith lower temperature non-equilibrium solidus corresponding ligatures and ligature magnesium-LRSM (MM) and magnesium-yttrium injected into the melt for 30 to 60 minutes before the start of the casting process.

Casting alloy is subjected to high temperature heat treatment (homogenization) on mode:
320-340oWith over 8-12 hours
next
400-420oC for 10-12 h
or
320-340oWith over 8-12 hours
next
480-500oC for 10-12 h
for alloys containing LRSM (MM), yttrium and CMA pressing, forging, forging closed die, at least in two stages:
Pre -
- temperature negreau workpiece and tool - 450-480oWith,
- temperature at the end of the deformation is not more than 500oWith,
- rate of strain (expiration date) is possible,
not less than 0.11/s
the degree of deformation is not less than 50%
(drawing ratio greater than 10.

The final
- heating temperature of the workpiece and tool 380-400oWith,
- rate of strain is not more than 0.011/s
- the degree of deformation of at least 25%
(drawing ratio greater than 10.

Method of hardening heat treatment of the alloy is carried out by mode:
Temperature - (18020)oC
Duration of heating cooling air - 50-150 h
Products of alloy in the form of granules, tilcepa, powder process of solid or liquid state at a temperature close (+10oC) temperature non-equilibrium solidus of the alloy, so that the plasticization of solid billets at the stage of filing the form contributed to their grinding in the process of sliding friction, including shear deformation (not less than 3 kg/mm2facilitate the transition of solid or liquid at the rate of injection, excluding the capture of gases.

Below are the results of the corresponding experiments for the claimed alloy composition and method of its processing.

Alloy 1
Zinc - 0,1-3,0
LRSM - 0,05-1,0
(one of the elements of this subgroup cerium, lanthanum, neodymium, praseodymium)
Manganese - 0,001-0,5
Aluminum - 0,001-0,1
Iron is 0.0001 to 0.05
Silicon is 0.0001 to 0.05
Magnesium - Rest
Experience 1. Were cast three of the ingot with an average composition and alloying components close to the boundary concentrations of the alloying elements 1.

In table. 1 shows the chemical composition of the produced alloys. From cast ingots manufactured by hot pressing rods with a diameter of 15 mm

In table.2 shows the data for the study of the mechanical and technological properties and microstructure of the proposed alloy compared to the prototype.

Alloy 1 though and provides a significant increase in ductility, toughness and processability during deformation in comparison with the prototype, however, as shown by the study of its structure, izmelchennost grain and the stability of the grain structure is insufficient. Therefore for grinding grain structure, ensuring its stability and improving the mechanical properties of the alloy 1 was add to the Elenia grain and stability of a homogeneous fine-grained structure in the alloy 1 must be added the modifier in the form of any one of the additives zirconium, calcium, strontium, calcium cyanamide (CaCN2) or any other effective inoculant alloy in an amount of 0.01 to 1.0% (alloy 2).

Experience 2. Were cast ingots three alloys with optimal structure and content of the alloying components, close to the boundary concentrations of the alloying elements 2.

In table. 3 shows the chemical composition of the produced alloys. From cast ingots manufactured by hot pressing rods with a diameter of 15 mm

In table.4 shows data on the study of the mechanical and technological properties and microstructure of these alloys and alloy prototype.

The elements of the subgroup for light rare earths (LRSM) or areaway subgroups REM is cerium, lanthanum, neodymium, praseodymium and less common items, Pm, Sm, EU.

Rare earth metals (REM) in the amount of fairly widely distributed in nature. Their content in the earth's crust is 0,016% and exceeds the content of such widely used in the industries of metals such as copper (0,01%), zinc (0,005%), tin (0,004%), lead (0,0016%). Moreover, the light REE are more common in the earth's crust than heavy REE (yttrium subgroup) and their content is 0,0093%. From light REE is the most common, and with great advantage by try and distribution he is in second place after cerium.

The most difficult and expensive operation upon receipt of REM is separate receipt due to the proximity of their physico-chemical properties. Therefore, when using the rare-earth metals as alloying components more efficiently and economically advantageous to use separate metals, and mixtures thereof, obtained in the process of refining minerals (raw materials) than the individual metals. Instead of separate metals from subgroups LRSM possible to use mixtures thereof. The most common and cheapest mixture LRSM is mischmetall (MM).

Mischmetall (MM) is an alloy of light rare-earth metals in approximately the proportions in which they are contained in ores (minerals). Mischmetall (MM) is obtained without separation or partial separation of individual rare-earth metals, which greatly simplifies the technology of its production and makes it cheaper than individual REE.

Mischmetall (MM) usually consists of cerium, the content of which varies between 50-76%, but could not go beyond these limits. Another major element in mischmetall is lanthanum, the content of which can vary in the range of 25-40%. In the MM composition may also contain neodymium - about 15%, presidivm - about 5%. The content of other rare-earth metals and impurities do not exceed the Eski from a mixture of cerium and lanthanum, what's even more cheaper this mixture.

It is also possible to use as the mixture LRSM a mixture of metals consisting of 85% of neodymium and 15% praseodymium (or 72% of neodymium, 9% lanthanum, 8% praseodymium, and the rest other rare-earth metals and impurities), which is called Didymium (D), and the cost is determined by the availability of the necessary raw materials (ore) from the manufacturer and features extraction technology specified REM from this raw material.

Experiments were conducted in which to reduce the cost of alloy 2 instead of one of the elements of the subgroups LRSM was introduced a mixture LRSM in the amount of 0.05 to 1.0%, usually mischmetall (MM) representing a mixture of (approximately) - 55% of cerium + 25% lanthanum + 15% neodymium + 5% praseodymium, or, much less frequently, didymium (Subject) having the approximate composition of 85% neodymium + 15% praseodymium (alloy 3).

Experience 3. Were cast ingots three alloys with optimal structure and content of the alloying components, close to the boundary of alloy 3. From cast ingots manufactured by hot pressing rods with a diameter of 15 mm

In table.5 and 6 show respectively the chemical composition, mechanical and technological properties and data on the study of the microstructure of these alloys and alloy prototype.

Yttrium refers to the, the n is the lightest of rare earth metals after scandium, respectively, 4,457 and 2,989 g/cm3. Yttrium 1.5-2 times lighter than other REE (6,17-9,83 g/cm3).

Yttrium is the most common and cheapest metal in their subgroup REM. The yttrium content in the earth's crust is several times higher than the content of other rare-earth metals of yttrium subgroup.

In natural compounds (minerals) in the amount of rare-earth metals of yttrium yttrium subgroup is contained in the greatest quantity and is much larger than the other elements. Therefore yttrium, including with regard to its low density, technically and economically more advantageous to use separate metal and not mixed with other rare-earth metals, as in the case of LRSM.

For yttrium characteristic is almost two times higher modulus of elasticity (E= 6,61103kg/mm2compared with LRSM (3,0-4,0103kg/mm2), and therefore we can expect a significant increase in the strength of interatomic bonds in the formation of his with alloys of magnesium-based solid solutions.

Yttrium has a significantly higher solubility in the solid magnesium compared to LRSM that determines the possibility of yttrium, LRSM and zinc in the solid magnesium at different temperatures (wt.%) are given in table.A.

Additional alloying alloys based on magnesium-yttrium contributes to a significant increase of the yield stress in compression, more intense than under tension. As a result these values are aligned.

For most magnesium alloys, with the exception of magnesium-lithium, the yield point in compression in 1,5-2 times lower than the yield strength tensile (anisotropy limits yield), which limits the use of magnesium alloys in structures operating under compressive loads. The above feature of magnesium alloys due to the nature of the deformation of the HCP structure magnesium.

Experiments were conducted in which to improve the strength properties of the alloys at elevated (150-250oC) and normal temperatures, including with the aim of reducing the anisotropy within the yield strength in tension and compression, in alloys 2 and 3 was added yttrium in the amount of 0.5 to 5.0% (alloy 4).

Experience 4. Were cast ingots three alloys with optimal structure and content of the alloying components, close to the boundary concentrations of the alloying elements 4, 5. From cast ingots produced by hot press the STW at temperatures of 20, 150 and 250oWith, including the yield strength in compression, and data on the study of the microstructure of these alloys and alloy prototype.

Given that the yttrium forms with oxygen, including high temperature, strong enough oxide film, experiments were conducted to assess the impact of small additives (0,01-0,5%) of yttrium on the oxidation featured alloys at high temperatures, including in the liquid state. It was shown that these additives yttrium reduce the Flammability of the investigated alloys (alloy 3) improve their casting properties, in particular the tendency to hot cracking, and stabilize fine-grained structure (alloy 5).

In some cases, the casting of ingots and castings of the proposed alloys it was found that izmelchennost grain increases, i.e., the effect of the modification increases depending on the ratio of the content in the alloy of small additives of iron and silicon. As a result of experiments, it was found that to enhance the effect of the modification present in the alloy alloying components and stabilization obtained in ingots and castings of fine-grained structure, the ratio of iron content to the silicon must be within 2-6 to 1.

Content is. the ti data were obtained by analysis of the investigation of the microstructure of the ingots and castings, which showed that at higher concentrations of these elements in the melt, the effect of the modification unstable and in certain types of ingots and castings is observed raznozernistoy and coarse grain.

Experience 5. Were cast ingots five formulations with different content of iron and silicon and close as possible on the content of other alloying elements. To cast ingots was investigated microstructure. The results of chemical analysis of alloys and data on the study of the microstructure shown in table.9.

Analysis of the results of investigations of mechanical properties of a large number of semi-finished products made of the proposed alloys showed that the most high and stable values of the ductility and toughness of the material, which determine the increased energy-absorbing ability of the material, observed in alloys containing alloying components in the following quantities, % (alloy 6):
Zinc - 0,1-2,0
LRSM (MM) - 0,05-0,2
Zirconia - 0,05-0,3
Yttrium - 0,01-0,5
Iron is 0.0001-0.01 to
Silicon is 0.0001-0,005
Manganese - 0,001-0,1
Aluminum - 0,001-0,02
The content of volatile components, as is acteristic and impact strength, while maintaining sufficient strength.

The ductility and toughness of the proposed alloy 2-4 times higher than the corresponding characteristics of the alloy of the prototype and other standard magnesium alloys (table.10 and 11).

The use of the alloy composition 6 for the manufacture of parts of the interior of automobiles, airplanes and other vehicles can significantly reduce the weight of products subject to the necessary security requirements of the materials.

In addition, it should be noted that the content of alloying elements is almost at the lower limit of the alloy with low density (about 1.75-1.77 g/cm3and relatively cheap, even relatively conventional magnesium alloys.

Investigation of mechanical properties of ingots containing yttrium, showed that higher values of strength at elevated temperatures (150-250oC) are observed for alloys in which the content of yttrium, LRSM (MM) and zirconium closer to the upper limit, and the zinc content should be 0.1 to 1.0% (alloy 7).

Chemical composition and mechanical properties at room temperature and temperatures of 150, 220 and 250oWith alloys that meet the composition requirements of alloy 7, are given in table.12 and 13.

Resistance/img>=2.5 kg/mm2(25 MPa) 1000 h, characterized by a residual deformation of the sample () amounted to 0,5%; 0.8% and 2.5%. The limits of creep (100of 0.2) at 150oWith alloys 7-2, 4 (max content) and alloy prototype, respectively, 14, 12 and 3 kg/mm2(140, 120 and 30 MPa).

The highest values of strength parameters, including yield stress in compression, under normal and cryogenic temperatures are achieved in the proposed alloy, if the content of the alloying components, zinc, yttrium, LRSM (MM), zirconium is closer to the upper limit (alloy 8). While retaining a high level of strength properties at elevated temperatures.

Chemical composition and mechanical properties of the investigated alloys are given in table.14 and 15.

The experiment for the manufacture of granules (powder) of the proposed alloy showed that the possibility of molding granules with higher temperatures and with high speed of crystallization of 102-106deg/s allow you to get an anomalously supersaturated solid solutions of yttrium, LRSM (MM), zirconium, zinc and manganese in solid magnesium, which makes it possible to maintain the content of these alloying leavine granules offer alloy, of which by hot compacting and pressing made rods with a diameter of 15 mm

The results of the study of the chemical composition of the proposed alloy and its mechanical properties are given in table.16 and 17.

As mentioned above, used in the proposed alloy alloying elements in the recommended quantities form the basis of alloy magnesium in most cases solid solutions with minor Perissinotto alloying components, and therefore the application of the hardening heat treatment (quenching + artificial ageing) to improve the strength properties is impractical. However, in the case where the proposed alloy is recommended as a structural material of high durability, application hardening heat treatment for alloys with alloying elements on the level close to the upper limit. Given that for magnesium alloys characterized by reduced diffusion activity of the atoms in the solid state when cooled from high temperatures, hardening in the decomposition of the supersaturated solid solution can occur without accelerated cooling from a high temperature (quenching), and only during artificial aging of the casting (product) and hot in combination with optimal plasticity of the proposed alloy with a high content of alloying element is zinc yttrium, LRSM (MM), zirconium (alloys 7 and 8) are obtained after artificial aging on mode:
Temperature - (18020)oC
The duration of heating at these temperatures - 50-150 h
The cooling - air
In table.18 shows the mechanical properties of the proposed alloy in hot-deformed and annealed condition.

We offer alloy can be manufactured in the form of ingots, castings, deformed semi-finished products and products in a variety of ways of processing. A necessary condition for the processing method proposed alloy is maintenance (preservation) of a homogeneous fine-grained (or close to that) the structure of the alloy, which, along with hardening effect of alloying elements defines a high level of physical-mechanical and service properties.

The production method of the proposed alloy includes batch preparation, melting alloy, refining, maturation melt casting, granules, ingots, turning ingots and hot deformation ingots for the manufacture of semi-finished products.

Conducted research and analysis experience with the proposed alloy showed that in order to reduce losses de ligatures. Ligatures magnesium-LRSM (MM), magnesium-yttrium, magnesium, zirconium, magnesium-manganese before the introduction of the melt is heated to a temperature of 20-50oWith lower temperature non-equilibrium solidus corresponding ligatures. Ligatures magnesium-LRSM (MM) and magnesium-yttrium injected into the melt for 30 to 60 minutes before the start of the process of casting ingots, castings, granules (powder).

The process reflects favorably on the homogeneous structure of the alloys is the high-temperature processing of ingots - homogenization.

When homogenization conditions for leveling diffusion under the action of which dissolve non-equilibrium eutectic and intermetallic compounds, is aligned with the chemical composition and properties of solid solution across the grain volume. Homogenization contributes to the creation and stabilization of the homogeneous grain structure and vnutrikabinnoe structure in hot-deformed semi-finished products, reducing and elevating the excess allocation in the alloy.

Given that the proposed is a multicomponent alloy and alloying elements in systems with magnesium have significantly different temperature physico-chemical transformations, this should be taken into account when selecting modes of homogenization splay and magnesium-LRSM (MM), respectively, in the temperature range 550-610o3oWith, and magnesium-zirconium - temperature peritectic 654oFrom, then offer alloy, it is preferable to recommend a two-step mode of a homogenizing annealing.

The first step is the dissolution of the fusible excess phases containing zinc.

Grade II - dissolution of excess phases containing yttrium, LRSM (MM), zirconium and manganese.

On the basis of the conducted research and the chemical, phase and structural composition of the proposed alloy, the temperature of the nonequilibrium solidus depending on alloy composition and temperature of the beginning of an intensive process of coagulation fragile skeletal components (allocations) alloy have been developed and proposed modes of homogenization of the ingot and large thick-walled castings.

I. 320-340oC - 8-12 h + 400-420oWith 10-12 hours

II. For alloys with a high content of yttrium, LRSM (MM), zirconium and manganese - 320-340oC - 8-12 h + 480-500oWith 10-12 hours

Cooling of the ingots after homogenization on the air.

In table. 19 shows the results of a study of microstructure and mechanical properties of bars and deformed semi-finished products after conducting a homogenizing treatment of the ingot.

practical properties of the proposed alloy showed stable homogeneous fine-grained (polygoncount) structure during hot deformation can be obtained only at the expense of full and spontaneous recrystallization. Temperature-speed conditions hot deformation depend on the content of alloying elements in the alloy and condition of the structure of the original piece.

To improve the grain structure of the structure of finite semi-finished products and products in this case you need to use the pre-deformed billet from the homogenized ingot.

As mentioned above, the grain structure (polygoncount) structure in hot-deformed semi-finished product is formed or in the process of deformation at high temperatures involving dynamic recrystallization, or after hot deformation due to spontaneous recrystallization occurring in alloys based on magnesium almost instantly, in less than 1-2 C.

Dynamic recrystallization takes place in the process of dynamic effects (deformation) on the structure at high temperatures, and spontaneous - in the process of metal cooling after hot deformation due to the energy accumulated during deformation.

Grain structure, resulting hot dermacentor not higher than the temperature of the last deformation, usually do not below 350-400oC.

Carried out researches have allowed to obtain the necessary data on temperature, speed and the degree of deformation of the proposed alloy, which allow you to create in a deformed semi-finished product (the product) of a homogeneous fine-grained (Polynesian) structure, which provides a strong mechanical and service properties of the semi-finished product.

Listed below are the technological parameters of the production of intermediate (hot-pressed) billet, forging (upsetting) and stamping products in relation to the manufacture of extruded disc road wheels of the proposed alloy with regulated homogeneous fine-grained (Polynesians) structure.

The mechanical properties of the drive motor of the wheel obtained by the proposed method of treatment, we offer alloy, 1.2-1.5 times higher than the properties of the drive wheels, made by known conventional technology.

It should be noted that the proposed alloy unlike other known strain standard magnesium alloys used for the manufacture of the disc wheel, alloys MA (Russia), ZK60A (USA) and others, due to its high processability during hot deformation allows p is the proposed method to obtain (hot deformation) of the proposed alloy, ensuring the creation of a regulated structure below:
I. compressing the intermediate pieces from the homogenized ingot:
- Heating temperature of the ingot and container - 450-480oWith, but so that at the end of the deformation temperature of the workpiece was not more than 500oC.

The drawing ratio is more than 10.

The flow rate of the metal is possible in the press, not less than 0.11/s

The proposed composition of the alloy and pre-homogenization bars allow you to extrude the billet with the allowable flow rate of metal while pressing up to 20 m/min, for comparison, the prototype - alloy MO - allows speed expiration to 2 m/min, alloy MA - up to 3 m/min.

II. Forging (upsetting) molded workpiece can be combined with the first stamping blanks on mode:
- Use the convexo-concave jaunty.

- Heating temperature of the billet and Boykov - 450-480oWith, but so that in the end the strain was not more than 500oC.

- The degree of deformation of more than 50%.

The strain - rate is the maximum possible, not less than 0.11/s

III. Preliminary stamping:
- Heating temperature of the billet and die - 400-450oC.

The strain - rate - not more than 0,51/s

the button in the final stamping across the cross-section of the workpiece would not be the volume of metal with a degree of deformation less than 20%.

IV. Final stamping disc road wheels:
- The final stamp should provide the most accurate stamping, in order, if possible, to reduce machining surface (drive wheels).

- Heating temperature of the billet - (40020)oC.

- The temperature of the stamp - (38020)oC.

The strain - rate - minimum on the press, not more than 0.011/s, i.e. the time of deformation of about 1 min at a degree of deformation of 50%.

- Indicative data on the required effort (pressure) for stamping - 10 kg/cm2. True voltage current required to fill a shape with a metal, in this case approximately 3-4 kg/mm2.

In table. 20 shows the mechanical properties of the samples manufactured by the above method and the traditional technology of the proposed alloy.

In the last decade become more and more widespread technology of manufacturing products of magnesium and other alloys from a solid-liquid state, and as source material (mixture) used crushed solid billet in the form of granules, tixocortol, powder. One such technology is Thixom, powder can be used for the manufacture of products, including thin-walled, with a wall thickness of 0.5-3 mm, with a high level of mechanical and service properties, density and surface quality.

Getting high physico-mechanical properties and quality is possible if the manufacturing of the products produced from solid or liquid state at temperatures close (+10oC) temperature non-equilibrium solidus of the alloy.

The treatment of solid billets of the proposed alloy is produced by a method in which plasticize solid billets at the stage of filing the form carries them grinding in the process of sliding friction, including with the participation of shear deformation to facilitate the transition of solid or liquid state with a viscosity and fluidity, providing a homogeneous alloy (melt) into the mold cavity with the speed (velocity respectively, excluding the capture of gases and creates the possibility of filling to obtain a sealed products with minimal porosity, good surface finish and dimensional accuracy, high physical-mechanical and service properties.

In table. 21 shows the mechanical properties of samples of the proposed alloy obtained by the method of I. M. about the mobile with the desired energy-absorbing properties, as for example the instrument panel, radiator grills, bumpers.


Claims

1. The base alloy of magnesium containing zinc, manganese, aluminum, iron, silicon and magnesium, characterized in that it further comprises at least one light rare earth metal (LRSM), selected from the group consisting of cerium, lanthanum, neodymium, praseodymium in the following ratio, wt.%:
Zinc - 0,1 - 3,0
LRSM - 0,05 - 1,0
Manganese - 0,001 - 0,5
Aluminum - 0,001 - 0,1
Iron is 0.0001 to 0.05
Silicon is 0.0001 to 0.05
Magnesium - Rest
2. Alloy under item 1, characterized in that it further comprises a modifier in the form of one of the additives containing from 0.01 to 1.0% zirconium, calcium or strontium.

3. Rafting on p. 2, characterized in that it contains a mixture of LSRM containing 55% cerium, 25% lanthanum, 15% neodymium, 5% praseodymium (MM mixture) or a mixture LRSM, containing 85 % neodymium and 15% praseodymium (mixture D).

4. Alloy under item 2 or 3, characterized in that it additionally contains 0.5 to 5.0% yttrium.

5. Alloy under item 2 or 3, characterized in that it further contains 0.01 to 0.5% yttrium.

6. The alloy according to any one of paragraphs.2-5, characterized in that the ratio of iron to silicon is (2-6): 1, and the content of manganese and aluminum, according to the and, wt.%:
Zinc - 0,1 - 2,0
LRSM (MM) - 0,05 - 0,2
Zirconia - 0,05 - 0,3
Yttrium - 0,01 - 0,5
Manganese - 0,001 - 0,1
Aluminum - 0,001 - 0,02
Iron is 0.0001 - 0.01 to
Silicon is 0.0001 - 0,005
Magnesium - Rest
8. Rafting on p. 4, characterized in that it contains components in the following ratio, wt.%:
Zinc - 0,1-1,0
LRSM (MM) - from 0.84 to 0.92
Zirconia - 0,69 - 0,81
Yttrium was 4.76 - 4,89
Manganese - 0,08 - 0,09
Aluminum - 0,012 - 0,018
Iron - 0,009 - 0,025
Silicon - 0,005 - 0,007
Magnesium - Rest
9. Rafting on p. 4, characterized in that it contains components in the following ratio, wt.%:
Zinc - 2,90
LRSM (MM) - 0,84
Zirconium - 0,76
Yttrium - 4,88
Manganese - 0,09
Aluminum - 0,018
Iron - 0.003
Silicon - 0,008
Magnesium - Rest
10. Rafting on p. 4, characterized in that it contains components in the following ratio, wt.%:
Zinc - 2,94
LRSM (MM) - 0,87
Zirconia - 0,72
Yttrium - 4,93
Manganese - 0,08
Aluminum - 0,015
Iron - 0,01
Silicon - 0,006
Magnesium - Rest
11. The processing method based alloy magnesium, which includes batch preparation, cooking melt the introduction into the melt alloys of magnesium, manganese, magnesium, zirconium, magnesium, yttrium and magnesium-LRSM, melt refining, its maturation and subsequent casting, olitorious to a temperature of 20-50oWith lower temperature non-equilibrium solidus corresponding ligature, ligature magnesium-LRSM and magnesium-yttrium injected into the melt for 30 to 60 minutes before the start of the casting process.

12. The method according to p. 11, characterized in that conduct casting to produce ingots, castings, granules, tixocortol and powders.

13. The method according to p. 12, characterized in that the obtained ingots are homogenized in a two-step mode: the first stage - at 320-340oC for 8-12 h, the second at 400-420oC for 10-12 hours

14. The method according to p. 12, characterized in that the obtained ingots of the alloys in accordance with p. 9 or 10 formula homogenized in a two-step mode: the first stage - at 320-340oC for 8-12 h, the second at 480-500oC for 10-12 hours

15. The method according to any of paragraphs.13 and 14, characterized in that conduct hot deformation homogenized ingot is produced by pressing, forging and stamping closed die at least in two stages, at this preliminary stage is carried out at a heating temperature of the workpiece and tool 450-480oC, the temperature of the metal at the end of the deformation is not more than 500oC, the strain rate is not less than 0.1 s-1the degree of deformation is not less than 50% or the drawing ratio is about 0.01-1the degree of deformation is not less than 25%.

16. The method according to any of paragraphs.11-15, characterized in that it further conduct final hardening heat treatment comprising heating to (18020)oWith a length of 50-150 hours and air cooling.

 

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Alloy magnesium // 2012642
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FIELD: powder metallurgy.

SUBSTANCE: parts of devices protecting against radioactive emission or electric contacts are proposed to be manufactured from tungsten/copper pseudoalloy. Tungsten powder is mixed with binder containing 0.5-1.5% colophony and 0.05-0.15% ammonium formate or citrate. Resulting mixture is compacted and resulting porous blanc is brought into contact with copper. The total is thermally treated by gradually raising temperature: first in vacuum to remove binder and to melt copper and then in argon atmosphere to 1360-1410оС.

EFFECT: increased wettability and uniformity of impregnation, and eliminated explosive risk due to excluded use of hydrogen.

3 cl, 1 tbl, 10 ex

FIELD: composites, in particular metalomatrix composites.

SUBSTANCE: metalomatrix composite containing copper matrix, silicium carbide reinforcing elements, and diamond submicron powder reinforcing particles. Volume ratio of silicium carbide elements and diamond submicron powder particles is 0.5-5. Invention is useful for electrical engineering, machine engineering, electronic industry, etc.

EFFECT: material with improved hardness, endurance and strength characteristic.

3 cl, 3 ex

FIELD: composites, in particular metalomatrix composites.

SUBSTANCE: metalomatrix composite containing copper matrix, silicium carbide reinforcing elements, and diamond submicron powder reinforcing particles. Volume ratio of silicium carbide elements and diamond submicron powder particles is 0.5-5. Invention is useful for electrical engineering, machine engineering, electronic industry, etc.

EFFECT: material with improved hardness, endurance and strength characteristic.

3 cl, 3 ex

FIELD: powder metallurgy, in particular electric contact materials.

SUBSTANCE: invention relates to carbon-copper composite. Material is produced from copper powder having purity of 99.9 % and black carbon powder with particle size at most 5 µm. Copper matrix has grid structure with through pores. One part of pores contains black carbon providing microstructure with carbon constituents. Parameter according to "International standard for annealed copper" is at least 40 %; density is at least 6.0 g/cm3. Copper powder is purified and annealed followed by blending of carbon and copper powders, double-side pressing under 500-1600 MPa, and sintering at 960-11000C.

EFFECT: material with increased density and conductivity and enhanced durability.

20 cl, 1 dwg, 7 tbl

FIELD: powder metallurgy, in particular electric contact materials.

SUBSTANCE: invention relates to carbon-copper composite. Material is produced from copper powder having purity of 99.9 % and black carbon powder with particle size at most 5 µm. Copper matrix has grid structure with through pores. One part of pores contains black carbon providing microstructure with carbon constituents. Parameter according to "International standard for annealed copper" is at least 40 %; density is at least 6.0 g/cm3. Copper powder is purified and annealed followed by blending of carbon and copper powders, double-side pressing under 500-1600 MPa, and sintering at 960-11000C.

EFFECT: material with increased density and conductivity and enhanced durability.

20 cl, 1 dwg, 7 tbl

FIELD: powder metallurgy, in particular electric contact materials.

SUBSTANCE: invention relates to carbon-copper composite. Material is produced from copper powder having purity of 99.9 % and black carbon powder with particle size at most 5 µm. Copper matrix has grid structure with through pores. One part of pores contains black carbon providing microstructure with carbon constituents. Parameter according to "International standard for annealed copper" is at least 40 %; density is at least 6.0 g/cm3. Copper powder is purified and annealed followed by blending of carbon and copper powders, double-side pressing under 500-1600 MPa, and sintering at 960-11000C.

EFFECT: material with increased density and conductivity and enhanced durability.

20 cl, 1 dwg, 7 tbl

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EFFECT: alloy of improved quality.

5 cl, 2 dwg, 4 ex

FIELD: powder metallurgy, in particular powder composites.

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EFFECT: matrix with increased hardness, wear resistance, and improved durability.

2 tbl

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