【摘要】 采用区熔定向凝固方法制备了<110>轴向择优取向的Tb0.3Dy0.7Fe2超磁致伸缩合金,在真空管式炉氩气保护条件下,对合金进行不同温度和时间的热处理,研究了不同处理时间、处理温度、冷却条件对该合金取向、组织、磁致伸缩性能以及力学性能的影响。结果表明:热处理不改变定向凝固形成的轴向择优取向;经930℃×2 h热处理后,网状的富稀土相基本转变为球状并均匀分布在基体相内,定向凝固形成的片层状组织发生退化,减小了REFe2相的磁畴在磁场中转动的阻力。细小的球状富稀土相均匀弥散分布在基体相内,减少了应力集中,因此提高了磁致伸缩性能和压缩强度;定向凝固Tb-Dy-Fe合金采用930℃×2h热处理后随炉冷却的工艺可以获得良好的综合性能,其饱和磁致伸缩为1226×10-6,压缩强度为256 MPa。更多还原

【Abstract】 <110> orient-ed Tb0.3Dy0.7Fe2 alloy was prepared by the method of zone-melting directional solidification.The effect of heat treatment temperature,time,cooling condition on the preferred orientation,morphology,magneto-striction and mechanical properties of TbDyFe alloy was investigated.The results show that the heat treatment does not change the axial preferred orientation.The net-shaped rich rare-earth phase becomes spheroidal after annealing treatment at 930 ℃ for 2 h,which distributes uniformly in the matrix phase resulting in the reducing of stress concentration.The resistance for REFe2 phase magnetic domain rotation is reduced due to the degradation of the lamellar microstructure formed in the directional solidification for the alloy after annealing treatment.The directional solidification TbDyFe alloy anneal at 930 ℃ for 2 h can get optimal performance with saturation magnetostriction of 1226×10-6 and compressive strength of 256 MPa.更多还原