Study on the process characteristics of vacuum hot pressing sintering of TiNiNb alloy based on “near net shape forming”

The TiNiNb pre-alloyed powder prepared after mechanical alloying was used as experimental material, and TiNiNb alloy was prepared by vacuum hot pressing sintering method (temperature 900℃, pressure 35 MPa, vacuum degree 1.6 × 10-3 Pa). The relative density and microstructure evoultion were analyzed by a serial of testing methods, such as: XRD and SEM etc. The results showed that the TiNiNb pre-alloyed powder presented amorphous state, the relative density of TiNiNb alloy after vacuum hot pressing sintering was 98.8%, and the alloy was completely crystallized. The microstructure of vacuum hot-pressed TiNiNb alloy is uniform, mainly composed of Ti-Ni matrix phase, β-Nb phase, (Ti,Nb)2Ni hard phase and a small amount of TiC impurity phase.