Geometric precision and microstructure evolution of TA15 alloy by hot shear spinning
(State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: To investigate the mechanistic influence of the deviation ratio and heating temperature on the hot shear spinning of TA15 alloy, the geometric precision and microstructure evolution of the hot-spun parts were experimentally investigated under different conditions. The results show that diametrical shrinkage occurs under a negative deviation ratio, and a sudden decrease in heating temperature creates a sharp increase in the shrinkage. A pronounced diametrical enlargement increases from the bottom location to the open end of the workpiece under a positive deviation ratio with a gradual decrease in heating temperature. The hot shear spinning process can lead to a non-uniform microstructure that results from the non-uniform deformation along the thickness direction. The distortion degree of the fiber microstructure formed near the outer surface increases with the decrease in the deviation ratio. A deviation ratio near zero and heating to a temperature within the desired range are beneficial conditions for obtaining spun parts with satisfactory geometric precision and a uniform microstructure.
Key words: titanium alloys; hot shear spinning; geometric precision; microstructure