Quantitative analysis of the orientation of lamellar α in TC17 titanium alloy

The orientation distribution of lamellar alpha in TC17 alloy was studied using quantitative metallography approach and finite element simulation. It is found that the orientation distribution of lamellar α varies with the value of strain. As the result, when the value of strain is below 0.38, the orientation distribution presents two symmetrical peaks, and the angle between the peaks is 90°, which indicates that lamellar α has a preferential orientation, and the microstructure shows a good agreement with initial lamellar microstructure. With the increase of strain, two asymmetric peaks appear in the orientation distribution of lamellar α, the volume fraction of lamellar α of one orientation peak increases and the angle between the peaks decreases. Initial basket structure is broken to different degree. When the value of the strain reaches about 0.7, the orientation approximately tends to present single-peak distribution with the preferential orientation of 80°~90°, lamellar α almost perpendicular to the direction of compression was observed.