First-principles calculation of twin boundary energy and strength/embrittlement in hexagonal close-packed titanium
Jun Hui, Xiaoyong Zhang, Tao Liu, Wenguan Liu, Biao Wang
Abstract
We performed first-principles calculations to determine the effects of 14 metallic solutes on twin boundary (TB) energy and strength/embrittlement in Ti alloys, with Ti {1 0 1¯ 2} and {1 0 1¯ 1} TBs as models. Twin formation energies were calculated to identify the effects of solutes on TB stability. Segregation energy and the associated segregation concentration and solubility energy were examined to identify the existence states of the solutes. The influences of solutes on TB strength were identified through strengthening/embrittling energy and its mechanical and chemical contributions. Tensile tests were performed using the “uniaxial-strain loading” and the “uniaxial-stress loading” methods to determine maximum TB strength.