Effect of cyclic heat treatment with hot deformation on the microstructure and structural orientation of TC17 titanium alloy lamellae
CHEN Shao-hua;ZHANG Mai-cang;JIA Meng-liu;PENG Tao;School of Materials Science and Engineering,University of Science and Technology Beijing;General Research Institute for Nonferrous Metals;
The effects of cyclic heat treatment and hot deformation on the spheroidization and orientation of the TC17 titanium alloy were investigated using a light microscope(LM) and electron backscattered diffraction(EBSD). The experimental results indicate that in the two-phase temperature range of a simple,cycle heat treatment,the spheroidization of the lamellar microstructure of the TC17 titanium alloy is finite. After cyclic heat treatment and compression deformation,the Widmannstatten structure disappears,the spheroidized α lamellae is more obvious,but the uniformity of its orientation is not greatly improved. In addition,the recrystallization velocity,and the strength and toughness of the two phases in deformation lead to a difference in their orientation,and the recrystallization velocity of the α phase is faster than that of the β phase. In the deformation process,the anisotropy of the α phase is preferentially reduced. On the other hand,during the hot deformation process,the degree of deformation of the α phase is lower than that of the βphase,because the α phase is harder than the β phase. The strain is primarily concentrated on the softer β phase adjacent to α phase,which produces greater uniformity in α phase than in the β phase.
【CateGory Index】： TG146.23;TG166.5