Prediction of Grain Size Uniformity in Hot Forming of TA15 Unequal Thickness Thin-Walled Shell

Aiming at the grain size uniformity of TA15 titanium alloy unequal thickness thin-walled shell during hot forming, the hot drawing process of TA15 titanium alloy unequal thickness thin-walled shell is simulated by the DEFORM-3D software platform. Based on the grain size evolution model of equiaxed α in TA15 titanium alloy, the microstructure distribution and possible defects are researched. Then the influence laws of process parameters, die structure parameters and blank structure parameters on the uniformity of grain size are revealed, and the reasonable die loading speed and blank size are determined. Through orthogonal experimental analysis, the significance of the parameters affecting the grain size distribution uniformity of TA15 unequal thickness thin-walled shell is determined. The quantitative relationship model between die structure parameters and grain size distribution uniformity is established by using response surface method, and the reasonable combination of parameters to meet the requirements of grain size distribution uniformity is determined. The results could provide guidance for the intergraded manufacturing in forming and modification of TA15 titanium alloy unequal thickness thin-walled shell.