Abstract
The authors tried to fabricate the shape memory alloy (SMA) particle dispersed materials by pulse electric current sintering and to investigate the microstructures of particle-matrix interface. Ti-Ni alloy was used as the dispersed particles and SCM435 steel powder was selected as the matrix. In the fabricated materials, Ti-Ni particles were dispersed uniformly and almost non-deformed in their shape. The relative density was about 95%. By EPMA and by TEM observations, we confirmed the segregation of Ti and Ni at the surface of dispersed particles, and also the diffusion of Fe into the particles. As the pulse electric current sintering method has advantages of shortening the time for fabrications and lowering the temperature for fabrication, the observed interface segregation layers were more thin in compare with other fabrication method such as HIP. When the crack arrest function is expected, these interface structures are considered to be favorable, because of eliminating the transformation temperature shift in Ti-Ni particles due to local composition change.
