抄録
In order to investigate the effect of Cr addition on the sintering of TiAl, We examined the relation between the Cr addition and the sintering behavior and sintered microstructure of TiH3+TiAl3 mixed powders, promising as a starting powder. We examined also the effect of β-phase on the sintering.
The results are as follows: (1) The Cr addition improves slightly the sinterability of the mixed powders, although it has a tendency to promote grain growth, especially in Al-and Cr-rich TiAl a significant grain growth takes place by high temperature sintering over 1620K. (2) The sinterability of the mixed powders is also improved with a decrease of Al content. This is probably due to the β-phase. However, its details are not clarified. (3) The amount of the p-phase increases in increasing Cr content. In relation to sintering temperature, with its rise γ/α2 lamellar structure increases in Al-rich TiAl, and the β-phase increases in Ti-rich TiAl as shown in the Ti-Al-Cr ternary system.