Abstract
Ti-Ni-Cu shape memory alloys were fabricated by powder metallurgy (P/M) process. The blended powders of three compositions of Ti-50.2at%Ni, Ti-40.2at%Ni-10at%Cu and Ti-30.2at%Ni-20at%Cu were milled using planetary ball mill. These powders were sintered using pulse-current sintering equipment. The effect of Cu addition on the shape recovery strain and critical stress for slip deformation of the alloys were investigated. Increase in Cu addition increases the shape recovery strain of the alloy, but it decreases the critical stress for slip deformation because of a number of pores formed by Cu addition. In the thermal cycling test, the plastic strain of the alloy of Ti-30at%Ni-20at%Cu was lower than that of the other alloys in an applied stress more than 75 MPa. The plastic strain of the alloy was 0.06% under an applied stress of 175 MPa.
