Effect of β-region Heat Treatment Conditions on Mechanical Properties of Ti-6Al-4V

This paper is concerned with the relation between the mechanical properties and β-grain size on the β-region solution heat treatment and over aging of Ti-6Al-4V alloy.When the delayed time was less than 20s on the β-STOA, tensile and yield strength showed constant values regardless of grain size. Elongation and reduction of area decreased gradually until the β-grain size grew up about 0.8 mm. They showed a tendency to be constant when the grain size was more about 0.8 mm.When the time was over 20s and the β-grain size was less than about 0.8 mm, tensile strength, yield strength, elongation and reduction of area had a tendency to be constant.On the other hand, when the grain size grew up about 0.8 mm over, tensile and yield strength showed a tendency to decrease gradually.These elongation and reduction of area showed a tendency to increase gradually.