Online ISSN : 1347-5320
Print ISSN : 1345-9678
ISSN-L : 1345-9678
Materials Processing
Development of a New Titanium Powder Sintering Process with Deoxidation Reaction Using Yttrium Metal
Akihiro IizukaTakanari OuchiToru H. Okabe
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2020 年 61 巻 4 号 p. 758-765


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 200–2000 ppm O by varying aY in the Y/Y2O3 equilibrium at 1300 K in NaCl–KCl (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 30–60 ppm O in YCl3 (l) in the sintering process, when the Y/YOCl/YCl3 equilibrium is employed. This study demonstrates the feasibility of a new sintering process that can control the O concentration in Ti to approximately 30–2000 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.

Fig. 5 Schematic illustration of the new sintering process developed in this study showing control of oxygen concentration in Ti. Fullsize Image
© 2020 The Japan Institute of Metals and Materials
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