SU1710188A1 - Method for production of magnetic powders based on alloys of rare-earth metals with transition metals - Google Patents

Abstract

The invention relates to the preparation of magnetic powders of rare-earth metals with transition metals. The goal is to simplify the process. The initial mixture containing the alloying components in the form of metals and their compounds is dissolved in a mixture of tetrachloride carbon with 10-90% dimethylformamide followed by heat treatment of the reaction mass at the decomposition temperature. The dissolution is carried out at a temperature of not more than 150 * 'C. 1 hp Formulas 2. • ^ The invention relates to the metallurgy of rare-earth metals, more precisely to the production of alloys of rare-earth metals with transition metals, specifically fio) r-teaching magnetic powders of alloys pi3 ^ M with transition metals. * A method is known for producing powders: alloys of type R -Co (where R is Sm, Pr, Gd, Ce), according to which the initial metals are melted to produce intermetallides. the melt is cooled. compact ^ material is ground (in ball or vibratory mills in acetone, toluene or an inert gas atmosphere) into a powder that is treated in a magnetic field to obtain a magnetic texture.11]. : One of the main disadvantages of the method is the mechanical grinding of a compact metal, which is accompanied by high energy costs. Moreover, pure metals are used as starting materials that need to be recovered from their compounds. A well-known method for producing metal powders (copper, nickel, cobalt, palladium, silver), according to which the powder of a thermally unstable metal compound is mixed with an organic liquid (glycerin, liquid paraffin, transformer oil) with m the ratio of thermally unstable metal compound and organic liquid 1:

Description

The effect is a method according to which REM oxide, cobalt powder, granulated calcium are mixed, the mixture is loaded into a steel container, which is placed in a furnace with a hydrogen atmosphere. The contents of the container were kept at 1 ° C 50 ° C for 3 hours. After cooling, the sintered mass of the reaction products was treated with wet nitrogen for several hours until it became a powder. Then the powder is mixed with water, the slag is transferred into the solution, and the alloy powder is filtered and dried in vacuum at a temperature not higher than 50 ° C.

The aim of the invention is to simplify the process of obtaining powders of magnetic alloys based on rare-earth metals,

This goal is achieved by the fact that the initial mixture containing the alloying components is first dissolved in carbon tetrachloride with 10-90% dimethylformamide followed by heat treatment of the resulting reaction mass with its decomposition, and the dissolution is carried out at a temperature not exceeding 150 ° C.

If the content of dimethylformamide (DMF) in a mixture with carbon tetrachloride (CCU) is less than 10% or more than 90%, then the metals and compounds containing the components of the resulting alloy will not dissolve in it.

When the content of DMF in a mixture with a CCU of 10-90%, a synergistic effect is observed with respect to the dissolution in it of metals and compounds containing alloy-forming components.

When the alloying components are dissolved at a temperature of more than 150 ° C, there is a sharp gassing and release of the reaction mass from the vessel.

An example. DMF and CCI4 are poured into a glass flask in a ratio that provides 10-90% DMF content in the solution, and REM and a transition metal compound (for example, chloride or acetate) are loaded into it in a given ratio or REM and transition metal in a given ratio, or REM alloy with transition metal. The flask with reagents is kept at room temperature or heated to a temperature of not more than 150 ° C until they are dissolved. Then the flask with the products is placed in an oven with a temperature of 500-600 ° С or the products are poured onto a surface heated to 500600 ° С. The result is

alloy powder or brittle mass of alloy particles, which are easily crushed, as well as gaseous products that are caught in the condenser. The resulting powders

The alloys possess magnetic properties and are attracted to a permanent magnet even without preliminary treatment in a magnetic field, which indicates their good quality.

0The effect of salt-extraction of DMF mixed with

ecu on the dissolution of alloying components shown in Table. one.

As follows from the table.1 when the content of DMF in a mixture with SCC less than 10% or more

5, 90% of the alloying components do not dissolve in it, and therefore the production of alloy powders is not possible. When the content of DMF in a mixture with ecu 10-90%, the alloying components dissolve in it, and when the resulting reaction mass is heated to 500-600 ° C, it decomposes to form alloy particles 5-30 µm in size, which are attracted to a permanent magnet .

5 In table. Figure 2 shows the effect of temperature on the dissolution of the alloying components.

From table 2 it follows that when the alloying components are dissolved in a mixture of

0 DMF and CC14 at a temperature of not more than 150 ° C, the dissolution process proceeds smoothly, which allows, after heat treatment of the reaction mass, to obtain magnetic powders of REM alloys with transition metals. The dissolution process at a temperature above 150 ° C is accompanied by the release of the reaction mass from the vessel with the loss of the alloying components.

Thus, according to the proposed method, a magnetic powder is formed directly during the heat treatment process of the reaction mass and immediately separated from its gaseous products.

5 thermal decomposition, while in the prototype during the heat treatment the reaction mass is maintained at 1150 ° C for 3 hours, after which the reaction mass is cooled and laborious and energy-intensive operations are performed to separate the metal from the slag. In addition, the proposed method, the heat treatment temperature may be lower (500600 ° C) than the prototype (1150 ° C). but

5, the heat treatment may be carried out in air.

The application of the proposed method allows to reduce the heating temperature of the reaction mixture from 1150 (according to the prototype) to 150 ° C below.

According to the proposed method, available cheap ecu and DMF reagents are used, while in the prototype relatively expensive calcium granules are used.

The proposed method can also be used to apply magnetic coatings containing alloys of rare-earth metals with transition metals.

.

Wssoeffective thermal decomposition of the reaction mass of the proposed method can be carried out in plasma.

The proposed method can recycle metal waste and momentum.

Formula 3 and Breasts

Claims (2)

1. A method of obtaining magnetic powders based on alloys of rare-earth metals with transition metals, including heating a mixture of alloying components in the form of metals or their compounds, is enough in order to simplify the process, with a mixture containing the alloying components, previously paq0, are taken up in a solution of carbon tetrachloride with 10-90% dimethylformamide, and the reaction products are heated at their decomposition temperature. 2. The method according to claim 1, about tl and h a y i and with 5 so that. In order to speed up the process, the mixture is dissolved at a temperature not exceeding 150 ° C. Table 1 Note. Use well-known istala magnetic slava. table 2