The master alloys for permanent magnets based on rare earth metals
(57) Abstract:The invention relates to the production of master alloys for permanent magnets on the basis of the metals. The master alloys for permanent magnets based on rare-earth metals contains, wt%: one or more rare-earth metals selected from the group of rare-earth metals containing neodymium, praseodymium, dysprosium, terbium 72 - 78, iron and/or cobalt - rest. The corrosion resistance of the alloys provided an opportunity for their long term storage in plastic containers, and the fragility of this material has simplified its use for the determination of the charge upon receipt of high-energy magnets based on rare-earth metals type REM2Fe14B. 1 table. The invention relates to the field of metallurgy, in particular the production of alloys of rare earth and transition metals of the iron subgroup for the issuance of these alloys and high-energy permanent magnets.The production of permanent magnets based on rare-earth metals involves receiving at the first stage base alloys doped or undoped. The alloys used for the manufacture of permanent magnets must have the following structure: the amount of REM (neodymium, praseodymium, dysprosium, terbium) 30-36 wt.%, if this is real Fe. Alloys of this composition can be prepared by the joint recovery of fluorides of rare-earth metals with FeF2, FeF3or their mixture, with the addition to the mixture FeB, powder metal iron and alloying elements . In one of the patents is proposed to use as a component of the charge of iron in the form of trichloride . In both cases, the recovery is carried out chips of metallic calcium. Due to differences in the raw materials and the conditions of the melt is not always possible to obtain an alloy of a given composition.There is a method of making permanent magnets from alloys obtained by fusing the individual components [3, 4]. The alloys are prepared by fusing the individual components of neodymium, terbium, dysprosium, iron, ferroboron, and alloying additives. For the preparation of an alloy of a given composition the estimated number of individual substances (REE, Fe, FeB, alloying additives) is melted in a crucible of alumina in induction furnaces, after which the melt is poured into the mould.The advantage of the method of producing alloys of the individual components is convenience in their synthesis and the possibility of obtaining alloys specified composition.However, for alloys the data metallotrejderskogo recovery anhydrous individual fluoride in an induction furnace in an argon atmosphere. Reductive smelting is carried out in the niobium or tantalum crucibles. To remove excess calcium individual REE (Nd, Pr, Dy, Tb) re-melt in vacuum in tantalum crucibles [5, 6]. Individual REE are characterized by high ductility and corrosion activity; therefore, to reduce losses during storage they are covered with a layer of paraffin and placed in a sealed package. The high plasticity of individual REE hampers their compartmentalisation in the air to catch the weight of material loaded for melting the composition of the charge.The disadvantages of the method of obtaining an individual REMS include the following:
the use of expensive crucibles for the production of metals and their melting;
the difficulty of storing and dividing into parts in the preparation of the charge for making alloys of a given composition;
significant power consumption for the heating system when the furnace metallothermic obtaining metal REM (Nd, Pr, Dy, Tb) and their subsequent remelting removal of slag and impurities including metal calcium .All of these factors significantly increases the cost price of the alloys obtained from individual REE.The closest analogue to the claimed izobreteniya, and as a rare earth metal samarium in the following ratio, wt.%:
Iron - 8-10
Cobalt - 20-35
Samarium - Rest
The alloy is used as alloys for permanent magnets .The difference between the claimed invention from the closest is that the ligature as REM contains at least one rare-earth metals selected from the group consisting of neodymium, praseodymium, dysprosium, terbium, as well as transition metals such as iron and/or cobalt in the following ratio, wt. %: at least one rare-earth metals selected from the group consisting of neodymium, praseodymium, dysprosium, terbium 72-78, iron and/or cobalt - rest.The problem solved by the invention was the development of the composition of the alloys to produce alloys used for the manufacture of permanent magnets, with the fragility and corrosion resistance in the air higher than the individual rare earths.The solution of this problem is provided by the fact that the proposed alloys based on rare-earth metals contains one or more rare-earth metals selected from the group consisting of neodymium, praseodymium, dysprosium, terbium, and jelly is - 72-78
Iron and/or cobalt - 100
The presence of ligatures REM number 72-78 wt.% provide for its high fragility and better corrosion resistance due to the formation of intermetallic compounds and low concentrations of free REE. The use of cheaper material ligatures REM-iron (cobalt) instead of individual REE provides for remelting obtaining alloy of a given composition.Retrieving ligature is illustrated by the following example:
Getting ligatures composition 72 Nd - 28% (wt.) Fe.For the manufacture 2000 ligatures used TRIFLUORIDE REE concentration of neodymium 69,8% (wt. ) and praseodymium 2,2% (wt.), TRIFLUORIDE iron with iron concentration of 50% (wt.). An excess of metallic calcium to restore metal fluoride amounted to 20% of the stoichiometric quantity.The excess of neodymium in the original mixture to obtain the required ligatures composition is 8%, so theoretical mass of the ingot is increased to 2115,2, From the calculated amount of iron in the composition of the alloy (560 g) 35% in the mixture introduced in the form of a powder of metallic iron (196 g) and 65% in TRIFLUORIDE, the amount of which amounted to 728, After calculation, we obtain the charge for in the Naya weight of the charge - 4231,The components of the mixture after weighing mix in the mixer, is loaded into a crucible, which is installed in the device recovery, and carry out the restoration. The apparatus of the recovery vacuum, filled with argon gas and electric blasting initiate the reaction of recovery. At the moment of passage of the reaction devices fix the elevated pressure and temperature. After rehabilitation melting apparatus is cooled to room temperature (18-30oC), then open and raise the crucible. From the crucible remove the ingot and slag, after which the ingot cleaned from slag inclusions and weighed. Weighing got a lot of ingot ligatures, equal 1980.3 g, which corresponds to the output 93,6%. From ingot was selected sample.Chemical analysis of the ingot showed the following results: Nd 70,1%, Pr Of 2.1%, Ca to 0.15%, Cu and 0.09%, Ni of 0.07%, Fe rest (wt.%).Chemical compositions and properties of the proposed ligatures are presented in the table.Offer ligatures these compositions synthesized at the Siberian Chemical combine. The corrosion resistance of the alloys provided an opportunity for their long term storage in plastic containers, and the fragility of this material has simplified its use for selection is energy magnets based on rare-earth metals type P3M2Fe14B. Proposed by the authors ligatures are used as substitutes for individual REE induction smelting magnetic alloys of any composition.Sources of information taken into account in the preparation of the description:
1. US 4612047 A, C, 22 C 33/00, 1986.2. FR 8666948 A1, C 22 C 23/06, 1988.3. US 4756775 A, H 01 F 1/04, 1988.4. Cecala I. B. , Samarin A. B. Physical metallurgy precision alloys. Alloys with special magnetic properties. - M: metallurgy, 1989, S. 458.5. Handbook of rare metals. Edited by ivy C. E. - M.: Publishing house "Mir" 1965, S. 585.6. Zelikman A. N. Metallurgy of rare earths, thorium and uranium. - M: GNTI 1961, S. 192.7. EN 2066269 C1, H 01 F 1/053, 3/08, 1996.8. SU 384922 A, C, 22 C 28/00, 29.05.1973. The master alloys for permanent magnets based on rare earth metals containing rare-earth metals and transition metals, characterized in that as REM it contains at least one rare-earth metals selected from the group consisting of neodymium, praseodymium, dysprosium, terbium, and as the transition metals iron and/or cobalt in the following ratio, wt.%:
At least one rare-earth metals selected from the group consisting of neodymium
FIELD: metallurgy; metallohydride alloys for thermal pumps, air-conditioners, cold generators.
SUBSTANCE: proposed metallohydride pair of alloys contains low-temperature and high-temperature alloys; low-temperature alloy has composition mm1-xLaxNi4CO(0.1≤x≤0.999) and high-temperature alloy has composition LaNi5-xAlx (0.001≤x≤0.5).
EFFECT: increased cold generating capacity of thermal pump at pressure in system not below atmospheric.
2 tbl, 1 ex
FIELD: non-ferrous metallurgy; methods of production of scandium-containing ligatures.
SUBSTANCE: the invention is pertaining to the field of non-ferrous metallurgy. The method of production of scandium-containing addition alloys includes a metallothermic restoration in halogenide melts. According to the invention the halogenide melt containing 1.0-1.4 mass % of scandium oxide is added with 1.4-1.7 mass % of zirconium oxide and conduct restoration by an alloy of aluminum with magnesium at the ratio of the halogenide melt to the aluminum-magnesium alloy from 1.2 up to 1.6. The technical result of the invention is production of a synthesized addition alloy containing scandium and zirconium with the maximal strengthening effect, decreased value of the produced addition alloy (by 30-40 %) due to decrease of consumption of the cost intensive scandium oxide by 50 %.
EFFECT: the invention ensures production of a synthesized scandium and zirconium ligature with maximal strength, allows to decrease significantly its production cost and consumption of expensive scandium oxide.
1 tbl, 1 ex
FIELD: compression refrigeration machines.
SUBSTANCE: regenerative material is defined by the formula R2O2S, where R represents at least one of rare-earth elements such as La, Ce, Pr, Nd, Sm, Eu, Cd, Tb, Dy, Ho, Er, Tm, Yb, Ly, and Y. The regenerator provided with nozzle made of regenerative material on the basis of rare-earth metal oxysulfide comprises oxysulfide of rare-earth metal defined by the formula R2O2S.
EFFECT: prolonged service life.
25 cl, 8 dwg, 17 tbl, 28 ex
SUBSTANCE: films and coatings made form proposed alloy can be used in the capacity of corrosion-resistant elements of control systems in precision instrument making, in the form of thin resistive films and coatings of circuit elements of resistance, operating at influence of corrosive mediums. Invention is directed to achievement of high corrosion stability in sea-water and increasing of processing characteristics at application of films and coatings. Optimal by achieved effect is alloy at following correlation of components, wt %: chrome 20.0-25.0; zirconium 5.0-9.0; cerium 0.1-0.9; germanium - the rest. Characteristics of proposed alloy: corrosion stability 0.001-0.005 mm/year, adhesion of films 8-12 MPa, cohesion of films 6.5-10.2 MPa. Films correspond nano-structured system with separation of nanoparticles of size from 30 up to 150 nm.
EFFECT: development of precision alloys with particular physicochemical properties, operating in corrosive mediums.
2 cl, 1 tbl
SUBSTANCE: method includes treatment of contact surfaces to remove oxide film, heating of contact surfaces and application of metal coating from gallium alloy by local contact melting. Removal of oxide film is made by chemical treatment of contact surfaces with the first etching solution with its subsequent neutralisation and cleaning of contact surfaces from etching results. Then mechanical cleaning of contact surfaces is carried out by polishing, afterwards contact surfaces are heated, metal coating of gallium alloy is applied in the medium of the second etching solution, and subsequent neutralisation of remains of the second etching solution is carried out.
EFFECT: improved loading capacity of knock-down electric contact joint during transfer of electric energy without change in design of contact joint, while the temperature mode of operation is within the permissible limit.
8 cl, 2 ex
SUBSTANCE: according to procedure there is used source charge containing sodium fluoride, potassium chloride, scandium oxide or fluoride, aluminium fluoride, hydro-fluoride of potassium and oxy-fluoride of zirconium and/or hafnium. Charge is mixed with metal aluminium to maintain weight ratio of components of charge to aluminium, as 1:0.8-1.1. Produced mixture is loaded into a crucible and is heated to temperature 800-900°C. Further, there is carried out alumino-thermal reduction at melt mixing. Melt is conditioned during 15-30 min and salt melt and liquid metal are poured separately into moulds. Source charge contains components at the following ratio, wt %: oxide or fluoride of scandium 4.3÷12.0, aluminium fluoride 5.0÷8.0, sodium fluoride 14.5÷18, potassium hydro-fluoride 1÷3, zirconium and/or hafnium oxy-fluoride 8÷15.4, potassium chloride - the rest.
EFFECT: improved modifying effect of alloying components, simplified process and reduced rotation of salts.
2 cl, 6 ex, 1 tbl
FIELD: process engineering.
SUBSTANCE: invention relates to soldering by gallium-based diffusion-curable solder and can be used for making permanent bonds of different materials, in particular, for low-temperature flux free soldering of metals and ceramics with metals. Solder to this end comprises copper, gallium and tin. Note here that it contains copper with particle size of 25-45 mcm and gallium-tin alloy at definite ratio of components.
EFFECT: low-viscosity high setting rate solder for flux-free soldering.
SUBSTANCE: proposed active material contains the alloy of composition formula SixTiyZnz, where each of x, y and z is the mass percent content satisfying the relationship x+y+z=100, 38≤x<100, 0<y<62 and 0<z<62. Negative electrode comprises said active material. Electric device represents a storage battery with active material of negative electrode.
EFFECT: high initial capacity at high cycling characteristics.
10 cl, 10 dwg, 1 tbl, 2 ex
SUBSTANCE: manufacturing method of rare-earth magnets involves a stage of bringing a compacted item obtained by hot processing in order to create anisotropy in a sintered item having a rare-earth magnetic composition in contact with alloy melt with a low fusion temperature, which contains a rare-earth element.
EFFECT: increasing a coercitive force without any addition of large amount of such rare-earth elements as Dy and Tb.
13 cl, 9 dwg
SUBSTANCE: invention relates to production of a rare-earth magnet. At the first stage a compacted powder part is produced from a powder including the main phase RE-Fe-B, where RE is at least one of either Nd or Pr, and the phase of inter-grain boundary around the main phase in the form of alloy RE-X, where X is a metal. Second stage involves hot deformation treatment of the compacted powder part to obtain magnetic anisotropy with production of a rare-earth magnet. Herewith the hot deformation treatment at the second stage comprises two steps, which represent an extrusion to produce a semi-finished product and settling of the semi-finished product. During the extrusion the compacted powder part is placed in a molding head to apply pressure to the compacted powder part with the help of an extrusion die with provision of reduced thickness of the compacted powder part to produce a semi-finished product shaped as a sheet, and during the setting pressure is applied to the semi-finished product shaped as a sheet in the direction of its thickness to reduce the thickness in order to produce the rare-earth magnet.
EFFECT: provided is production of a rare-earth magnet with high degree of orientation over its entire area and high residual magnetization.
6 cl, 18 dwg, 4 tbl