α(α2)/γ PHASE EQUILIBRIA IN Ti-Al-C AND Ti-Al-B TERNARY SYSTEMS

α（α２）／γＰＨＡＳＥＥＱＵＩＬＩＢＲＩＡＩＮＴｉＡｌＣＡＮＤＴｉＡｌＢＴＥＲＮＡＲＹＳＹＳＴＥＭＳ①ＬｉＪｕｎｔａｏ，ＨａｏＳｈｉｍｉｎｇＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｒｉｎｇ，Ｎｏｒｔｈｅａｓ...

The α(α 2)/γ phases equilibria in Ti Al X(X=C, B) ternary system at low C and B concentrations was measured by EPMA and examined with thermodynamic analysis. The results show that the addition of C in Ti Al binary system results in the (α(α 2)+γ)/γ boundary shifting to Al rich side, whereas the α(α 2)/(α(α 2)+γ) boundary shifting little, and that the addition of B results in both of α(α 2)/(α(α 2)+γ) and (α(α 2)+γ)/γ bountaries shifting to Al rich side. The solubilities for C and B in α(α 2) phase are larger then those in γ phase therefore C and B are α phase forming elements in Ti Al binary system.