Isothermal section of the Ti-Si-Ga system in the Ti-rich corner at 1350 deg C

Phase equilibria in the Ti-Si-Ga system were investigated by physico-chemical analysis methods (metallography, XRD and EPMA) in a limited composition range of below 31 at.% Ga and above 62 at.% Ti at 1350 deg C for the first time. The Ti sub 5 (Si,Ga) phase on the Ti sub 5 Si sub 3 compound base exists up to about 25 at% Ga. It coexists with the phases of the Ti-Ga system ( beta , Ti sub 2 Ga and Ti sub 5 Ga sub 3 ) and forms an extended two-phase region beta +Ti sub 5 (Si,Ga) sub 3 , a narrow region Ti sub 2 Ga+Ti sub 5 (Si,Ga) sub 3 , and two three-phase fields, Ti sub 2 Ga+Ti sub 5 (Si,Ga) sub 3 +Ti sub 5 Ga sub 3 and beta +Ti sub 5 (Si,Ga) sub 3 +Ti sub 2 Ga. The solubility of silicon in Ti sub 2 Ga and in Ti-based phases is small.