Spherical titanium alloy powder is a material made of qualified molten titanium alloy liquid metal by atomization, rotary electrode or vacuum vacuum atomization, then hot extrusion into rod, hot isostatic pressure into titanium alloy turbine disk, aircraft keel joint, seawater desalination device, etc. The sintering of spherical titanium alloy powder is usually solid-phase diffusion method. When the alloy elements in titanium alloy are prepared by mixed element method, it is found that the alloy elements in titanium alloy will appear instantaneous liquid phase or provide diffusion channel to promote densification process during sintering process, which is also called strengthening sintering. The realization of the sintering process of spherical titanium alloy powder depends on three basic conditions, namely solubility criterion, segregation criterion and diffusion criterion. In general, the matrix in the additive shall be: having a greater solubility or forming an intermediate compound, and the solubility of the additive in the matrix shall be small. This is mainly due to:

1. The solubility of the additive in the matrix is small, which will lead to the precipitation of the additive at the interface between the spherical titanium alloy powder particles, which is conducive to the diffusion of the matrix.

2. The low solubility of additives in the matrix can reduce the dosage needed to maintain the sintering. Moreover, densification of the reinforced sintering is the process of the matrix diffusion to the additive. The diffusion is beneficial to the rapid growth and elimination of the pore of the sintered neck of the spherical titanium alloy powder. If the solubility of the additive is large, the diffusion will occur opposite to the former, and the Kirkendall effect will appear, the porosity will increase, and the sintering experience expansion.

Secondly, the additive can precipitate on the interface between the spherical titanium alloy powder particles during sintering and can be maintained throughout the sintering process. The precipitation formed a diffusion interface between the powder particles rich in additives. Therefore, a channel for rapid diffusion of matrix is provided. The liquid and solid phases of the matrix and the phase diagram of the added elements continue to decrease. When the solubility standard and precipitation standard of full football titanium alloy powder are concerned, the sintering effect of additives depends on the influence of the additive on the diffusion rate of the matrix materials. The faster the material diffusion is, the better the sintering effect is.