时效时间对FeNiCoAlNbB合金组织和性能的影响

Influence of aging time on microstructure and mechanical properties of Fe Ni Co Al Nb B alloy

以Fe39.35Ni30Co18Al10.5Nb2B0.15形状记忆合金为研究对象,运用X射线衍射仪、扫描电镜、压力试验机、金相显微镜和能谱仪研究了时效时间对合金组织结构和性能的影响。结果表明,随着时效时间的增加,γ'相和B2相相继析出,γ'相的析出强化了奥氏体母相,B2相的析出降低了合金的塑性。从伪弹性曲线可以看出,在873 K温度下时效时,随着时效时间的增加,合金的抗压强度、可恢复应变和硬度均随着时效时间的增加呈现先增大后减小的趋势,而合金的最大应变则随时效时间的增加先快速后缓慢增大。时效时间为60 h时,合金的抗压强度、可恢复应变及硬度均达到最大值,分别为1239.05 MPa、10.76%、496 HV10,合金的残余应变相对最小。

Based on Fe39.35 Ni30 Co18 Al10.5 Nb2 B0.15 shape memory alloy as research object , effects of aging time on microstructure and mechanical properties of the alloy were investigated by means of X-ray diffraction, SEM, pressure test machine, metallurgical microscope and energy disperse spectroscopy .The results show that with aging time increasing , γ′phase and B2 phase precipitated successively , the precipitation of γ′phase strengthens the austenite matrix , and the precipitation of B2 phase reduces the ductility of the alloy .The pseudo-elasticity curves show that aged at 873 K, with aging time increasing , the compressive strength , recoverable strain and hardness of the alloy increase at first and then decrease .However , the maximum strain of the alloy increases rapidly at first and then slowly increases .When the aging time is 60 h, the compressive strength , the recoverable deformation and the hardness of the alloy all reach maximum and is 1239.05 MPa, 10.76%and 496 HV10, respectively.But the residual strain of the alloy is relatively minimal .