Sintering Response and Equiaxed α-Ti Grain Formation in the Ti Alloys Sintered from Ti@Ni Core–Shell Powders

Using Ti@Ni core–shell powder is in favor of enhancing the sintering densification, obtaining the linear shrinkage response, forming equiaxed α-Ti grain, and reducing the oxygen contamination, compared to the elemental powder mixtures. The enhanced sintering densification is responsible for the improved tensile strength, while a combination of the equiaxed α-Ti grain formation, the low oxygen increment, and the reduced porosity content noticeably doubled the tensile ductility. The linear shrinkage response is good for accurately controlling the dimension of the sintered parts. All of the improved issues are largely attributed to the unique dissolution phenomenon of Ni from Ti@Ni core–shell powder. The detailed mechanism will be discussed in this paper.