In this work, deoxidation and decarburization of crude tantalum prepared by carbon reduction of Ta$-2$O5 with Ar plasma arc heating has been investigated by using H2-Ar plasma arc melting. The oxygen and carbon contents obtained by carbon reduction smelting are dependent on the carbon to Ta2O5 mixing mole ratio, and the product of (%O) and (%C) in each tantalum is almost constant. Therefore, the carbon/oxygen ratio in tantalum can be adjusted by changing the C/Ta2O5 ratio for the refining process that follows. At the subsequent stage of H2-Ar plasma arc melting, oxygen in tantalum can be quickly liberated but carbon is scarcely removed. As a result, ductile tantalum whose sum of oxygen and carbon is less than 100 mass ppm can be produced by the deoxidation effect of H2-Ar plasma arc melting for a high oxygen- and low carbon-bearing tantalum. Deoxidation is mainly caused by dissociated and activated hydrogen atoms in the H2-Ar plasma gas.
|Number of pages||9|
|Journal||Nippon Kinzoku Gakkai-si|
|Publication status||Published - 1988 Sep 1|
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