Effects of Extrusion on Microstructure and Properties of Ti75 Alloy Tubes

Ti75 alloy tubes were prepared by using hot extrusion method, and the effects of extrusion temperature and extrusion speed on microstructure and properties studied. The results show that the extrusion temperature has significant influence on both shape and content of α phase. When the extrusion temperature increases from 800℃ to 850℃, the volume fraction of primary α phase decreases, and the balling of the acicular α phase in transformed β, with the α phase becoming round and coursing. Meanwhile, strength of the alloy decreases and the ductility improves slightly. The extrusion speed of between 60 mm/s to 80 mm/s has limited effect on the microstructure and properties of the alloy.