热处理工艺对Fe-15Mn-4.5Si-10Cr-5Ni系形状记忆合金析出相及形状记忆性能的影响

为了进一步提高Fe-15Mn-4.5Si-10Cr-5Ni系形状记忆合金的形状记忆效应,利用OM、TEM及物理相分析等试验方法,研究了直接时效及固溶+时效热处理工艺对试验合金微观组织、第二相析出及形状记忆效应的影响。结果表明,试验合金经固溶处理后,因第二相粒子大幅度回溶,导致试验合金形状记忆性能下降较为明显;同时,因直接时效处理较固溶+时效处理显著提高了试验合金中Cr碳化物第二相析出量,使试验合金形状记忆性能大幅度提升。其中,试验合金在800 ℃直接时效可获得最佳形状回复率。

Effect of heat treatment process on precipitates and shape memory properties of Fe-15Mn-4.5Si-10Cr-5Ni shape memory alloy

Effects of direct aging, solution and aging heat treatment on the microstructure, precipitation of the second phase and shape memory effect of the tested alloy were studied by means of OM,TEM and physicochemical phase analysis in order to further improve the shape memory effect of Fe-15Mn-4.5Si-10Cr-5Ni shape memory alloy. The results show that,the shape memory performance of the specimen decreases obviously because the second phase particles redissolve greatly after solution heat treatment; At the same time, the direct aging treatment significantly increases the amount of Cr carbide second phase precipitation in the specimen compared with the solution and aging treatment, which greatly improves the shape memory performance of the specimen. The best shape recovery ultimately can be obtained by direct aging at 800 ℃.