Effect of the initial microstructure on the deformation behavior of Ti60 titanium alloy at high temperature processing

Abstract

Based on the stress–strain data from the isothermal compression test in a wide range of temperature and strain rate, the effect of initial microstructure on the deformation behavior of Ti60 titanium alloy at high temperature processing was analyzed. The beta heat treated specimen with fine acicular Widmanstätten microstructure and the alpha–beta forged specimen with duplex microstructure were tested. The constitutive equation and the processing map were established for this alloy with two different initial microstructures. The results show that the initial acicular and duplex microstructures of Ti60 alloy exhibit different deformation characteristics below beta transus and the similar deformation characteristics above beta transus. With the spheroidization of lamellar phase, the calculated activity energy of the Ti60 alloy with acicular microstructure is much larger than that duplex microstructure, and the processing map also exhibits a big difference. The research provides a basis for determination of the forging process of Ti60 alloy based on the different initial microstructures.