Ni過剰Ti-Ni合金に生成する非金属介在物相の安定性に及ぼすNi濃度とC/O比の影響

抄録

The effects of Ni concentrations and carbon to oxygen (C/O) ratios on the phase formation during the commercial production process and morphology of nonmetallic inclusions were investigated in Ni-rich Ti-Ni alloys. In the process from casting to forging, a phase change from Ti(C, O) to Ti₄Ni₂O_X occurred depending on the Ni concentration and C/O ratios. The phase change from Ti(C, O) to Ti₄Ni₂O_X was easy to proceed in the alloys with low Ni concentrations and C/O ratios, whereas the Ti(C, O) was stable in the alloys with high Ni concentrations and C/O ratios.

Fig. 5　SEM-BSE images of cross sections in three Ni-rich forged alloys with C/O ratio of 0.8 and 1.5.