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

Three kinds of SMAs with different composition Fe-30Mn-6Si,Fe-30Mn-6Si-1Ni,and Fe-30Mn-6Si-1Ni-1Ti were prepared with melt spinning.The microstructure of these alloys were analysed with X-ray diffraction(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 recovery strain of Fe-30Mn-6Si-1Ni-1Ti is higher than Fe-30Mn-6Si-1Ni.The Fe-30Mn-6Si-1Ni-1Ti shows the highest shape recoverystrain 2% when then pre-strain was 3%.