材料期刊网

The α(α2)/γ phase equilibria in Ti-Al-X (X = C, B, Fe, Si in at. pct) ternary systems were studied by equilibrium heat-treatment and EPMA. The results show that the addition of B to the Ti-Al binary system leads to a shift of both α(α2)/[ α(α2)+γ] and [α(α2)+γ]/γ phase boundaries to Al-rich side and 0.1 B addition decreases Tα by 18℃. The addition of C leads to a shift of [α(α2)+γ]/γ phase boundary to Al-rich side but the effect of 0.2 at.pct C addition on Tα is very slight. The addition of Fe results inα(α2)/ [α(α2)+γ] and [α(α2)+γ]/γ phase boundaries shifting to Ti-rich side and 1.0 Fe addition increases Tα by 90~110℃. The addition of Si leads to a shift of α(α2)/α(α2)/ [α(α2)+γ]} phase boundary to Ti-rich side and the 0.3 Si addition increases Tα by 80~110℃. The solubilities for C, B and Si in α(α2) phase are higher than those in the γ phase but the solubility for Fe in α(α2) phase is lower than that in γ phase.