Tensile behavior of Ti-22Al-24Nb-0.5Mo in the range 25-650 °C

The tensile and fracture behavior of an orthorhombic alloy Ti-22Al-24Nb-0.5Mo (at%) with three types of microstructure were investigated in the temperature range between 25 °C and 650 °C. The O+bcc microstructure (basketweave lath type) possesses an elongation maximum at 500 °C and its drop at 650 °C has been attributed to dynamic strain aging as suggested by previous investigators. The α2+bcc microstructure has the highest room temperature elongation (εf >18%) and the cause of the elongation drop at 650 °C is suggested to be the fine O phase precipitates from the bcc phase. An optimal balance between strength and plasticity was achieved in the α2+O+bcc microstructure.