Nb对FeNiCoAlNb多晶形状记忆合金超弹性的影响

Effect of Nb on superelasticity of FeNiCoAlNb polycrystalline shape memory alloy

通过微观组织观察,物相分析,超弹性分析,硬度实验研究Nb含量对固溶时效处理后的Fe41.5-xNi30Co18Al10.5Nbx（x=0,1,2,3,at%）多晶形状记忆合金超弹性的影响。结果表明：该合金具有较高的压缩超弹性,当Nb含量为2%,在873 K下时效60 h时达到最高压缩超弹性14.01%,最大硬度505.34 HV;合金中析出相β相、γ＇相以及基体内的未溶解σ相三者的大小、数量和分布共同影响着合金的形状记忆性能;其中细小均匀分布的γ＇相和σ相增强了基体的强度,有利于合金超弹性性能的提高,β相分布于晶界处不利于合金的性能。

The effect of Nb content on superelasticity of Fe41.5-xNi30Co18Al10.5Nbx（ x = 0,1,2,3,at%） polycrystalline shape memory alloys after solid solution and aging treatment was investigated by means of microstructure observation,phase analysis,superelastic analysis,and hardness test. The results show that the alloy has high compression superelasticity,when the Nb content is 2%,the alloy aged at 873 K for 60 h exhibits the highest compression superelasticity of 14. 01% and the maximum hardness of 505. 34 HV. The size,quantity and distribution of precipitated β phase,γ＇ phase and σ phase in the matrix affect the shape memory properties of the alloy. The fine and uniform γ＇ phase and σ phase enhance the strength of the matrix,which is conducive to the improvement of superelasticity properties of the alloy. The distribution of β phase at grain boundaries is not conducive to the properties of the alloy.