热处理对深过冷快速定向凝固Fe-Ga合金组织和性能的影响

Influence of heat treatment on microstructure and properties of deep undercooled and rapid-directionally solidified Fe-Ga alloys

Fe-Ga合金后续的热处理工艺同合金的成分配比、制备工艺一样,对合金的磁致伸缩性能有重要影响.采用熔融玻璃净化与循环过热相结合的方法,制备深过冷快速定向凝固〈110〉轴向取向的Fe83Ga17合金棒材,分别采用高温和低温淬火工艺,研究淬火前后合金的组织和磁致伸缩性能.结果表明:快速定向凝固Fe83Ga17合金从不同温度淬火至室温,合金在TC附近淬火获得较高的磁致伸缩应变,淬火可抑制有序DO3相的形成,与高温淬火工艺相比,在TC附近淬火,只有部分特定区域优先得到淬火,发生modified-DO3相转变,并部分保留高温无序组织,最终获得有序-无序的室温组织,这种组织有利于Fe-Ga合金磁致伸缩性能的提高.

As the preparation process and composition ratio,the subsequent heat treatment will have important influence on the magnetostrictive properties of Fe-Ga alloys.By means of glass fluxing purification and cyclic superheating,the deep-undercooled rapid-directionally solidified alloy Fe83Ga17 with〈110〉axial orientation was prepared.Then the alloy Fe83Ga17 was quenched at high temperature and low temperature respectively to investigate its microstructure and magnetostrictive properties before and after the quenching.The result showed that,quenched at different temperature until at room temperature,the alloy Fe83Ga17 achieved higher magnetostrictive strain at about TC,indicating that quenching process could restrain the formation of ordered DO3 phase.Compared with high temperature quenching process,only part of particular area was quenched prior when quenching at about TC,so that modified-DO3 phase change took place.The disordered phase was partially retained.Finally,at room temperature,an ordered-disordered structure was obtained,which would be advantageous to the improvement on magnetostrictive properties of Fe-Ga alloys.