Response of Ti6321 titanium alloy at different strain rates under tensile loading

To investigate mechanical properties of Ti6321 titanium alloy, tensile tests at different strain rates are carried out. The changes of microstructure and properties at the range of 10(-3) s(-1)-10(5) s(-1) have been studied. Lower density and larger size of dimples produce when stretched at high strain rates of 10(3) s(-1) compared to quasi-static stretching. The yield strengths of the alloy are 805, 1096 and 2440 MPa at strain rates of 10(-3) s(-1), 2 x 10(3) s(-1) and 10(5) s(-1), respectively with obvious strain rate strengthening effect. At 10(5) s(-1) strain rate, parallel twins generate at grain boundaries to coordinate the deformation when dislocations cannot meet indicating the twinning mechanism comes into play.