放電プラズマ焼結法により作製したTZM合金の強度特性に及ぼす炭化物および窒化物系添加材の影響

抄録

In this study, TZM alloy and Titanium Carbide (TiC) and Titanium Nitride (TiN) added TZM alloy sintered bodies were fabricated by spark plasma sintering. Density, Vickers hardness and average grain size of sintered bodies were evaluated. Vickers hardness values increased with an increase in containing of additives in TZM. TiC added TZM sintered bodies had higher hardness compared to TiN added TZM sintered body. This difference could be due to difference in hardness of the additives. Densities decreased with increasing in containing of additives, because additive has lower density compared to TZM alloy matrix. Precipitates with size approximately 1μm were observed mainly at grain boundary in TZM-10vol%TiC sintered body. This size of precipitate was corresponding to primary particle size of TiC. It was speculated that TiC additives were mainly dispersed along grain boundaries. Value of Vickers hardness predicted with compound rule compared to that obtained with experiment. Experimental values were higher than calculated values. TiC and TiN added TZM alloy sintered bodies were strengthened by dispersion strengthening mechanism of additives but not only mixing of hard particles.