EFFECTS OF MICROSTRUCTURE AND OXYGEN CONTENT ON THE FRACTURE BEHAVIOUR OF THE #alpha# + #beta# TITANIUM ALLOY Ti-4Al-4Mo- 2Sn-0.5Si wt. Percent (IMI 550)

摘要

The effect of microstructure and oxygen contenton the room temperature tensile strength and fracture toughnessof the #alpha# + #beta# titanium alloy Ti-4Al-4Mo-2Sn-0.5Siwt. percent (IMI 550), are assessed in this paper, studied byvarying the solution treatment temperature and oxygen content.A detailed micromechanical study indicates that failure iscontrolled by interfacial regions between primary #alpha# andtransformed #beta# and at interfaces within the transformed#beta#. A transmission electron microscopy characterisation ofsuch interfacial regions has also been undertaken and has beenrelated to variations in both microstructure and oxygen content.