Sintering of titanium

In contrast to hot pressing technology, powder metallurgy titanium is prepared by cold pressing sintering process, generally using fine titanium powder as raw material. The fine titanium powder is a by-product of the production of "sponge titanium". The powder, called "sponge titanium powder," is produced by reducing titanium tetrachloride with sodium or magnesium. The particles are soft and irregular in shape, so they are suitable for cold pressing. In the United States, sodium reduced sponge titanium powder is preferred for the preparation of powder metallurgy titanium products, while in the former Soviet Union, it was reported that similar powders were made by molten salt electrolytic reduction method.

Another type of titanium powder is a pre-alloyed powder, made from alloy ingots by an ultra-pure process such as the plasma rotating electrode method. The particle shape of this powder is spherical, and it is difficult to use ordinary methods to press and form at room temperature. However, the powder can be fired into a porous structure or coating under loose loading conditions.