Rare-earth-based high-entropy amorphous alloy high in magnetocaloric effect and preparation method thereof

Abstract

The invention discloses a rare-earth-based high-entropy amorphous alloy material high in magnetocaloric effect. The molecular formula of the rare-earth-based high-entropy amorphous alloy is GdaCobAlcYdMe, wherein a, b, c, d and e represent the atom percentage content of the corresponding element, a is larger than or equal to 24.8 and smaller than or equal to 25, b is larger than or equal to 8 andsmaller than or equal to 25.4, c is larger than or equal to 24.8 and smaller than or equal to 25.4, d is larger than or equal to 5 and smaller than or equal to 15, e is larger than or equal to 10 andsmaller than or equal to 20, a+b+c+d+e is equal to 100, and M is one of Dy, Er and Ho. On the basis of a GdCoAly high-entropy amorphous alloy, M is used for replacing Y, the high-entropy amorphous alloy high in magnetocaloric effect is obtained, the alloy is stable in magnetocaloric performance, the magnetic variation temperature range is wide, and elements likely to volatile or oxidize are not included. In addition, the completely amorphous structure of the high-entropy amorphous alloy needs no crystallization heat treatment, the preparation process is simple, and the high-entropy amorphous alloy material has good magnetocaloric performance and has good application prospects in the technical field of magnetic refrigeration.

Description

technical field [0001] The invention relates to a rare earth-based high-entropy amorphous alloy magnetic refrigeration material technology, in particular to a rare-earth-based high-entropy amorphous alloy with large half-peak width and high magnetocaloric effect and a preparation method thereof. Background technique [0002] Since the 21st century, the contradiction between man and nature has become increasingly prominent, and environmental issues have become important issues affecting people's living standards and future development. Global warming has become one of the main threats to the world's environmental security, and the greenhouse gases that cause global warming have gradually become an important consideration for governments to formulate environmental policies. Therefore, there is an urgent need to develop a refrigeration material that is green, safe, high in refrigeration efficiency and does not emit greenhouse gases. Different from the traditional gas mechanica...

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Problems solved by technology

When strict environmental protection requirements made it difficult to continue traditional compression refrigeration, people began to do a lot of exploration on new magnetic refrigeration materials, and prepared a series of magnetic refrigeration materials with giant magnetocaloric effects, including Gd 5 (SixGe1-x) 95 , MnFeGeZn, DyYCo, LaFeCoSi and their hydrides and other series alloys, these alloys show a giant magnetic effect, and a large magnetic entropy change near the Curie temperature, but these materials have a narrow magnetic phase transition temperature range and poor cooling capacity

Chinese patent CN102965562A discloses a magnetic refrigeration material with giant magnetocaloric effect, Mn 2-x Fe x Ge z Zn z , 0.8≤x≤0.9, 0.2≤y≤0.27, 0.001≤z≤0.002, the maximum magnetic entropy change is higher than 26Jkg -1 K -1 However, in order to obtain the crystal structure of its single-crystal phase compound, mechanical ball milling and high-temperature sintering are required. The preparation process is complicated and energy-consuming, which greatly increases the time and energy costs for industrialization, hindering its practical application.

However, the alloy has poor forming ability, and its relative magnetic refrigeration capacity is only 325Jkg -1 , which greatly limits the application of the alloy

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