Study on the spinning process of cylinder-conical composite curved generatrix workpiece of TA15 titanium alloy

As a high specific strength structural material with excellent room and elevated temperature strength and thermal stability, TA15 titanium alloy is widely used in the field of aircraft, missiles and engine for the purpose of lightweight. According to the characteristic of cylinder-conical composite curved generatrix workpiece, the forming of thin-wall curved generatrix workpiece of TA15 titanium alloy was studied using hot spinning method. Shear spinning preforming was adopted, and multi-pass power spinning and conventional spinning were used to form the final workpiece. A multi-pass spinning process of curved generatrix workpiece from the plate blank was investigated through FEM simulation and process experiment. The forming process was analyzed and the mechanisms of spinning defects were revealed. The microstructural evolution results show that the grains are crushed after shear spinning and then elongated along the axial direction and circumferential direction during multi-pass composite power spinning and conventional spinning. The microstructure was refined and the uniformity was improved after shear spinning preforming and multi-pass composite spinning process. The uniaxial tensile test results of the as-spun workpiece showed that the strength increased significantly while the peak strain decreased slightly compared with those of the initial material.