Role of Ti sub(3)Al/silicides on tensile properties of Timetal 834 at various temperatures

Extremely fine coherent precipitates of ordered Ti sub(3)Al and relatively coarse incoherent precipitates of S sub(2) silicide exist together in the near alpha -titanium alloy, Timetal 834, in the dual phase matrix of primary alpha and transformed beta . In order to assess the role of these precipitates, three heat treatments viz. WQ, WQ-A and WQ-OA, were given to have no precipitates, Ti sub(3)Al and silicide and only silicide precipitates in the respective conditions. Tensile properties in the above three heat treated conditions were determined at room temperature, 673 K and 873 K. It was observed that largely Ti sub(3)Al precipitates were responsible for increase in the yield strength and decrease in ductility in this alloy.