加工对吸氢La0.6Pr0.4Fe11.4Si1.6B0.2合金磁热稳定性的影响研究

Processing effect on the hydrogenation of La0.6Pr0.4Fe11.4Si1.6B0.2 magnetocaloric alloy

摘要:

采用工业原料和感应熔炼法制备出La0.6Pr0.4Fe11.4Si1.6B0.2板锭，通过高温短时退火获得NaZn13型主相合金，进行氢化处理并研究了合金颗粒尺寸对吸氢处理后La0.6Pr0.4Fe11.4Si1.6B0.2氢化物磁热性能的影响。外形尺寸3-5 cm的大尺寸样品在吸氢后出现严重粉化，呈层片状剥离的破碎状态，但心部仍保持完整块状。外形尺寸小于1 cm的小尺寸样品吸氢后形状保持完好。La0.6Pr0.4Fe11.4Si1.6B0.2合金存在吸氢粉化临界尺寸。采用外形尺寸小于1 cm的样品吸氢能够防止合金氢化粉化现象发生，有利于铸造样品直接吸氢获得一定尺寸和几何形状的块状La0.6Pr0.4Fe11.4Si1.6B0.2Hx样品。

Abstract:

Thick plate of La_0.6Pr_0.4Fe_11.4Si_1.6B_0.2 alloy was produced with industrial raw materials by induction melting method and NaZn₁₃ type magnetocaloric phase was obtained by annealing at high temperature for short time. The annealed alloy was hydrogenated with various shapes and sizes. The bulk sample with a size of 3-5 cm was broken to powders from the outside to inside like an onion with a smooth ball shape center part left during the hydrogenation process, while the small samples with sizes less than 1 cm still hold their original shapes. The critical crack size for the La_0.6Pr_0.4Fe_11.4Si_1.6B_0.2 alloy was 1 cm on hydrogenation to avoid breaking down to powders. The processing could be used to develop La_0.6Pr_0.4Fe_11.4Si_1.6B_0.2H_x alloys with a certain sizes and shapes directly from casting alloy by hydrogenation absorption.