Preparation method of carbonic rare earth-ferrum, cobalt and silicon compound with NaZn1 structure

Abstract

The invention provides a preparation method of carbonic rare earth-ferrum, cobalt and silicon compound with NaZn1 structure, belonging to the technical field of magnetic refrigeration material; in the invention, a vacuum induction furnace is adopted for smelting, vacuumizing is carried out to above 2*10-1Pa, the pressure of common argon is from -0.05MPa to -0.02MPa, the smelting temperature is more than from 50 DEG C to 200 DEG C than the melting point, the smelting time is from 3-20min; the material is poured into a casting mould with red copper material to obtain mother alloy after being smelted, annealing treatment is carried out to the smelted mother alloy, so as to prepare the carbonic rare earth-ferrum, cobalt and silicon compound with 0.1-0.4 of C atom content alpha. The method can prepare the carbonic rare earth-ferrum, cobalt and silicon compound with more than 3mm of bulk mass, the annealing time is greatly shortened, and the obtained carbonic rare earth-ferrum, cobalt and silicon compound belongs to second-order phase transition without heat stagnation and magnetism stagnation, the performance is stable and reliable, Curie temperature can be regulated to more than room temperature, and the carbonic rare earth-ferrum, cobalt and silicon compound is applied to the magnetic cooling air-conditioning technology and wide magnetic refrigeration technology.

Description

technical field [0001] The invention belongs to the technical field of magnetic refrigeration materials, and in particular provides a method for preparing a simple carbon-containing rare earth-iron-cobalt-silicon compound. Background technique [0002] In recent years, since magnetic refrigeration technology is considered to be one of the next-generation new refrigeration technologies that are environmentally friendly, efficient and energy-saving, the exploration and research of magnetic refrigeration materials with huge magnetic entropy change has attracted great attention. Especially with NaZn 13 The rare earth-iron-cobalt-silicon compound of phase is recognized as the most practical magnetic refrigeration material due to its low price of raw materials and large change of magnetic entropy. However, NaZn is directly formed from the rare earth-iron-cobalt-silicon melt 13 The 1:13 phase of the type structure is very difficult. Under normal solidification conditions, the 1:1...

AI Technical Summary

Problems solved by technology

However, the existing problems are, firstly, it is difficult to obtain large blocks of materials larger than 2mm after quenching, and the quenching speed is too fast, and the thin strips or particles obtained are very brittle, and then after subsequent annealing and sometimes necessary hydrogenation After the project, a large part of it is pulverized into a powder of the order of magnitude less than 0.1mm, which cannot be used

However, the preparation method described in this patent uses electric arc furnace smelting, and it needs to be annealed at 900°C to 1100°C for 7 to 30 days. Such a long annealing time is not conducive to the application of this compound

And as we all know, the method of preparing materials by electric arc furnace is generally only used for the preparation of small samples in units of grams, and the preparation of materials above the kilogram level is likely to cause uneven composition

Images