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Oxygen (O) contamination in titanium (Ti) is difficult to control using conventional Ti powder-metallurgy technologies, owing to the strong affinity between Ti and O. In this study, we developed a new sintering process that can remove O from Ti by placing Ti green and yttrium (Y) in molten salt. This study demonstrates that the O concentration in Ti can be reliably controlled in the range of 2002000 ppm O by varying a Y in the Y/Y 2 O 3 equilibrium at 1300 K in NaClKCl (l), such that the sintering reaction of Ti powder simultaneously proceeds. Furthermore, it is also shown that the O concentration in Ti can be reduced to 3060 ppm O in YCl 3 (l) in the sintering process, when the Y/YOCl/YCl 3 equilibrium is employed. This study demonstrates the feasibility of a new sintering process that can control the O concentration in Ti to approximately 302000 ppm O. The process ensures economical rationality because the cost of Y metal is negligibly small in recent years. By developing this process, inexpensive high-O-concentration Ti powder can be applied for fabricating the desired low-O-concentration Ti products.

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