Research of twist-bend forming and performance control of titanium alloy wide-chord hollow fan blade under elevated temperature

A unified viscoplastic constitutive model was established to predict the microstructure and damage evolution of diffusion bonded (DB) titanium alloy during the hot twist-bend forming based on the results of elevated temperature uniaxial tensile experiments. The influence of physical internal variables were considered by the viscoplastic model, which uses a genetic algorithm to optimize the parameters. Then, Abaqus and its subroutine Vumat were used to simulate the evolution of grain size, dynamic recrystallization (DRX) fraction, and damage evolution of titanium alloy hollow fan blades during hot stamping. By comparing the simulation results with the experimental results, the application of the unified viscoplastic model is proved to be reliable. Finally, the fan blade body manufactured by twist-bend forming under the process of Part-800-10-6 is smooth, without surface defects, and forming quality is better. The research results can provide guidance for the mass manufacturing of TC4 titanium alloy wide-chord hollow fan blades.