Mechanical processing and microstructure of nickel-titanium by equal channel angular extrusion

The behavior of NiTi was determined under non-isothermal conditions at 700 deg C, 750 deg C, 850 deg C and 950 deg C and ram speed 25 mm/s. This paper summarized the work on the equal channel angular extrusion (ECAE) behavior of the NiTi alloy, which is hot-worked via non-isothermal ECAE. Processing at each of the three temperatures via ECAE can refine the initial coarse grains of NiTi (as-received) through shear deformation after first pass. The optical microscopy revealed that the developments of microstructure are quite different under different hot-working conditions.