Effects of equal channel angular extrusion and aging treatment on R phase transformation behaviors and Ti_3Ni_4 precipitates of Ni-rich TiNi alloys

摘要

Ni-rich TiNi alloys were subjected to the effect of multiple equal channel angular extrusion (ECAE) treatments by B_C path at 500 °C The characteristics of R phase transformation in aging treatment were dissimilar in the appearance and the temperature range to those counterparts induced by ECAE treatments. The fine lens-like shape Ti_3Ni_4 particles precipitated mainly in the regions of near grain boundaries and on the tangled grain boundaries after ECAE treatments. The effects and mechanisms of aging treatments and ECAE treatments on R phase transformation behaviors and Ti_3Ni_4 precipitates were investigated and discussed.