Sintering properties of Ti-27Nb alloys prepared by using Ti/TiH₂ powders under argon and hydrogen sintering processes

In the present study, Ti-27Nb alloy specimens were prepared from Ti/TiH₂ powders using Nb powders through the argon sintering process (ASP) and hydrogen sintering process (HSP). X-ray diffraction and scanning electron microscopy studies were conducted, and the sintered density, Vickers hardness, and Rockwell hardness of the Ti-27Nb alloys produced by different sintering processes, as a function of the vacuum sintering temperature (1350–1450 °C), were measured. The results showed that the Ti-27Nb alloy sintered bodies with the highest density and hardness were obtained by HSP. In addition, the pore size and number of HSP specimens were smaller and less than those of the ASP specimens. It was found that the Ti-27Nb alloy, produced by HSP, can prevent the formation of oxide layers, resulting in enhanced densification and hardness. Furthermore, HSP can also prevent the formation of hydrides and eliminate the dehydrogenation step. At the same time, the problem of brittleness and failure caused by hydride formation could be solved.