a magnetic refrigeration ho x tb y m z High entropy alloy and its preparation method

Abstract

The invention belongs to the field of magnetic refrigeration alloys in high-entropy materials, and relates to a magnetic refrigeration HoxTbyMz high-entropy alloy and a preparation method thereof. The high-entropy alloy has a chemical formula of HoxTbyMz; the atomic percents of all components are as follows: x not more than 35 and not less than 5, y not more than 35 and not less than 5, wherein M is one or more in Gd, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Dy, Er, Tm, Yb, Lu and Y, Z not more than 90 and not less than 30, and x+y+z=100; and the high-entropy alloy material is formed under general vacuum suction casting conditions, is low in heat hysteresis effect, has magnetic entropy change even exceeding metal Gd and high magnetic refrigeration capacity, can reach a highest refrigeration temperature section of 190 K, and is an excellent magnetic refrigeration material near the room-temperature range. The high-entropy alloy is broad in application prospect and unique in purpose in such daily life goods with high quantity and wide application as household magnetic refrigerators and household magnetic air conditioners and in the national defense field.

Description

technical field [0001] The invention belongs to the field of magnetic refrigeration alloys in functional materials, in particular to a Ho alloy with large magnetic entropy change and magnetic refrigeration capacity x Tb y m z A high-entropy alloy material and a preparation method thereof. Background technique [0002] Human life in modern society is increasingly inseparable from refrigeration technology, ranging from small to people's daily life, such as household air conditioners, refrigerators, food freezers, car air conditioners, to central air conditioning, gas liquefaction, industrial and agricultural production, etc. The freon used in traditional gas refrigeration has a destructive effect on the atmospheric ozone layer. The commonly used artificially synthesized alternative refrigerants usually have a strong greenhouse effect, and developed countries have legally stipulated that they stop using them in stages. At the same time, traditional refrigeration technology c...

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Problems solved by technology

[0005] 1) Since high-entropy alloys are new metal materials, magnetic refrigeration alloys have not been invented in the high-entropy alloy series;

[0006] 2) It is difficult to find materials with large magnetic entropy changes, and even many alloys have smaller magnetic entropy changes than pure Gd;

[0007] 3) Rare earth elements are usually directly used as magnetic working fluids, and their purification will cause a large economic burden

[0008] Due to the above reasons, the use of existing magnetic refrigeration materials is difficult to meet the current application requirements, which hinders the further development of magnetic materials; in addition, high-entropy alloys as magnetic refrigeration materials can be used in a wide temperature range Achieving a large magnetic entropy change, and applying rare earths in the form of high-entropy alloys can save costs

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