Numerical Simulation and Analysis of Hot Extrusion Preforming of Powder Titanium Alloy Valve

Due to low cost and good properties, the use of powder metallurgy titanium alloy in automobile industry to reduce weight and improve performance has been approved by automobile manufacturers. Based on the finite element method, the hot extrusion preforming process of Ti6Al4V powder titanium alloy valve was numerically calculated, and the influences of billet temperature, extrusion speed and extrusion ratio on temperature distribution and porosity were analyzed. The results show that temperature and deformation degree are the main factors affecting densification. Increasing extrusion ratio and billet temperature can improve densification. The temperature rise at the die exit are the highest. Taking the phase transition temperature of Ti6Al4V powder titanium alloy as the critical temperature, the critical curve of temperature rise under different extrusion ratios were obtained. It provides a reference for the selection of valve forming process parameters.