Mechanism and process optimization of extrusion cracking of TA15 titanium alloy shell

Aiming at the problem that TA15 titanium alloy shell has severe cracking defects around the shell due to uneven material deformation resulting in large adjoint stress during hot extrusion , by combining numerical simulation and experiment, the experimental parameters of TA15 titanium alloy shell were improved and optimized to reduce the temperature difference at the thin wall and avoid cracking defects. The initial temperature of the inner surface of the hot extrusion die was increased by pre-extruding the hot process material, the lubrication condition of the contact surface between the die and the shell was improved by using glass lubricant, and the heat loss during the extrusion process of the shell was reduced at the same time. The results show that the temperature difference at the thin wall of the shell can be successfully controlled to less than 100℃ by means of simulation and prediction. Experiments were carried out with reference to numerical simulation process parameters, the feasibility of the process method is verified, and the corrugated extrusion cracking problem of TA15 titanium alloy is solved.