单辊旋淬法制备含Ti的Fe基形状记忆合金的组织与性能

Microstructure and shape memory property of Ti containning iron-based shape memory alloys prepared with melt spinning

采用单辊旋淬法制备了3种不同组成的Fe基形状记忆合金(shape memory alloy,SMA):Fe-30Mn-6Si、Fe-30Mn-6Si-1Ni、Fe-30Mn-6Si-1Ni-1Ti。采用X射线衍射仪(XRD)、金相显微镜(OM)、扫描电子显微镜(SEM)分析了合金的成分及结构,通过拉伸实验测量合金的形状恢复率。结果表明,在Fe-30Mn-6Si合金中,除奥氏体晶粒外出现少量枝晶偏析,其二次枝晶臂间距为0.2μm。Fe-30Mn-6Si-1Ni、Fe-30Mn-6Si-1Ni-1Ti中等轴奥氏体晶粒均匀分布,且后者晶粒较大。预变形量为1%,1.5%时,Fe-30Mn-6Si-1Ni的形状恢复率高于Fe-30Mn-6Si-1Ni-1Ti;预变形量为2%时,Fe-30Mn-6Si-1Ni-1Ti的形状恢复率高于Fe-30Mn-6Si-1Ni;预变形量为3%时,Fe-30Mn-6Si-1Ni-1Ti的形状恢复率出现最大值2%。

Three kinds of SMAs with different composition Fe-30Mn-6Si,Fe-30Mn-6Si-1Ni,and Fe-30Mn-6Si-1 Ni-1 Ti were prepared with melt spinning.The microstructure of these alloys were analysed with X-ray diffrac-tion (XRD),optical microscope (OM)and scanning-electron microscope (SEM),the shape recovery strain of the alloys were measured by tensile test.Dendrite spikes appears in Fe-30Mn-6Si,the dendrite arm spacing was about 0.2μm.Equiaxial austenite grains distributed uniformly in Fe-30Mn-6Si-1Ni and Fe-30Mn-6Si-1Ni-1Ti, the grain size in Fe-30Mn-6Si-1Ni-1Ti was bigger.When the pre-strain was 1% and 1.5%,the shape recovery strain of Fe-30Mn-6Si-1Ni was higher than Fe-30Mn-6Si-1Ni-1Ti.When the pre-strain was 2%,the shape re-covery strain of Fe-30Mn-6Si-1Ni-1Ti is higher than Fe-30Mn-6Si-1Ni.The Fe-30Mn-6Si-1Ni-1Ti shows the highest shape recovery strain 2% when then pre-strain was 3%.