Abstract
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.
