The method of obtaining vodorodopodobnykh alloys of complex composition

 

The invention relates to metallurgy, and in particular to obtain alloys, which enables the absorption and release of hydrogen. In the way are at least four remelts with subsequent crystallization rate of the ingot is less than 0.6 mm/s, and a final melting with subsequent crystallization rate of the ingot than 0.6 mm/sec. the Invention allows hardware to improve the performance of the process of obtaining alloys based on rare-earth metals in 2.5 times and ensures alloys with high performance, stable properties for use as components of heat pumps, hydrogen accumulators. table 1.

The invention relates to the field of non-ferrous metallurgy, namely to obtain alloys, which enables the absorption and release of hydrogen.

Known alloys - hydrogen absorbers are made on the basis of compounds of the type AB₅in which place loaded with alloying components. They find their application in chemical power sources, electrochemical generators, batteries, hydrogen, heat pumps.

The main technical characteristic that defines the quality is the amount of hydrogen can decarbonate alloy in a predetermined range of pressures at a given temperature. The use of the particular composition of the alloy determines the possibility of extending the working range of pressure and temperature.

The process of obtaining alloys hydrogen absorbers consists of two basic operations: a fusion of the original components of the charge and solidification of the ingot. The fusion is carried out usually in the induction or arc furnaces (B. C. Linchevsky, "metallurgical Technique experiment", Moscow, metallurgy, 1979, p. 16).

Induction furnace for heating and melting can be open or closed. When working with vodorodomobilej alloys type AB₅melting lead in a closed induction furnace in an argon atmosphere due to the high oxidizing ability they are composed of rare earth metals (REM). Power supply furnaces are tube or machine generators of various capacities. The mixture of the alloy is placed in a crucible is a container located inside the inductor. The number of REM included in the charge, the charge excess in the calculation of the stupor. Next, the furnace vacuum, filled with argon and carry out soldering of the components of the charge. At the end of melting off the current, the alloy is poured into the mold, where it is crystallization.

The disadvantages of induction melting should be considered and, as a consequence, to decrease the working moderadamente.

A method of obtaining vodorodopodobnykh alloys of complex composition in arc furnaces with a non-consumable electrode. As the electrode is used tungsten. Furnaces operate in an atmosphere of neutral gas (argon). Molten metal (charge) have to be cooled in the mold under the electrode. When you enable arc material is melted, when you turn off the melt crystallizes, forming an ingot of the metal (alloy). The operation of melting and crystallization are performed several times. As the material of the mold is applied copper (B. C. Linchevsky, "metallurgical Technique experiment", Moscow, metallurgy, 1979, S. 21).

Smelting in furnaces of this type have the metal homogeneous chemical composition. The chemical interaction between the material of the mold and the alloy is missing. Therefore, from the point of view of consistency of purity alloys arc melting has the advantage over induction.

The disadvantage of the traditional method is the poor reproducibility of the results moderadamente alloys and the implementation of how extremely small the download source of the charge.

The technical result of the claimed method of producing Vodickova performance by increasing the mass of the melted ingots and stable getting high moderadamente alloys.

This is achieved in that in the method of obtaining vodorodopodobnykh alloys complex, comprising multiple melting the starting components and the crystallization of the ingot in arc furnaces with a cooled mold in an atmosphere of neutral gas, according to the invention at least four refining is carried out with subsequent crystallization rate of the ingot is less than 0.6 mm/sec, and a final melting is performed with subsequent crystallization rate than 0.6 mm/sec.

The essence of the method lies in the fact that the modes of crystallization under other equal conditions (material, design of moulds and so on) on the first remelts provide complete fusion of the components of the charge and chemical homogeneity of the alloy, and on the final remelting subsequent crystallization rate of the ingot leads to the optimal phase composition, the desired microstructure and related work moderadamente.

Currently in the literature there are no data on the effect of solidification conditions of the ingot to its specifications and, in particular, the hydrogen capacity. Meanwhile, at the stage of crystallization of the ingot is formed, the required microstructure and phase composition of the alloy, provide delaet all other parameters of the process of obtaining the alloy and at the same time lends itself well to technological control and mathematical description, the selected speed of solidification of the ingot, expressed in mm/sec. The lack of information about such studies is accompanied in practice, unstable, poorly reproducible or even low values of moderadamente alloys.

Substantiation of the parameters of the Declared parameters of the method of obtaining vodorodopodobnykh alloys of complex composition are optimal, since the melting conditions under which subsequent crystallization rate of more than 0.6 mm/sec at the stage of 1-4 remelts, will be accompanied by nipropriami and will lead to the chemical heterogeneity of the ingot. Thus, the main objective 1-4 remelts - to ensure chemical homogeneity of the ingot on its length.

Crystallization of the ingot after the fifth remelting with a speed of 0.6 mm/s leads to disruption of the microstructure and phase composition of the alloy, and consequently, to reduce the working moderadamente (see table). The main task of this stage is obtaining the maximum possible working moderadamente alloy.

It should be noted that the ingot obtained by traditional technology with the same process parameters (material and design of the mold, the arc parameters and so on) has a lower weight and work is t the need to reduce the weight of the melted ingot, in order to provide a simultaneous and chemical homogeneity, and the maximum hydrogen capacity of the alloy.

The application of this method of melting, as can be seen from the table that allows to raise cyclic performance 2.5 times, that is, to provide an opportunity to increase 2.5 times the mass of the melted ingot while maintaining its qualitative and quantitative characteristics. The claimed invention may with the same technical result to be applicable to all known compositions of alloys hydrogen absorbers.

An example of the method of obtaining vodorodopodobnykh alloys of complex composition In a water-cooled copper mold downloaded the mixture of alloy Mm_{for 0.9}La_{a 0.1}Ni₄With. A lot of mischmetall and lanthanum took with 3% excess based on the frenzy. To obtain an ingot weighing 2 kg of the composition of the components of the charge the following: mischmetall 600 g, lanthanum 66 g, Nickel 1082 g, cobalt 272, Next, the furnace was evacuated to a pressure of residual gases 0,006 mm RT.article and filled with purified argon. The first 4 remelting was carried out at a subsequent crystallization rate of 0.44 mm/sec (see table). The average current melting 350 And when U=60 C. After each remelting the ingot turned. After the fifth remelting implemented is working the hydrogen capacity of the obtained ingot in the pressure range 35-5 ATI was 1.52% by mass.

Thus, the claimed invention allows hardware to improve the performance of the process of obtaining vodorodopodobnykh alloys of type AB₅on the basis of REM 2.5 times and to obtain alloys with high performance, stable properties for use as components of heat pumps, batteries, hydrogen, chemical current sources.

Claims

The method of obtaining vodorodopodobnykh alloys complex, comprising multiple melting and crystallization of the ingot in arc furnaces with a cooled mold in an atmosphere of neutral gas, characterized in that at least four of the refining is carried out with subsequent crystallization rate of the ingot is less than 0.6 mm/s, and a final melting is performed with subsequent crystallization rate of the ingot than 0.6 mm/s