Strain-path-dependent texture evolution and strength enhancement mechanisms of near-alpha titanium alloy during the spinning forming process: Experiments and crystal plasticity simulations

During the spinning forming process, modifying the strain path provides a cost-effective method for tailoring the crystallographic texture and the mechanical properties of materials, especially for the metal with hexagonal close-packed (HCP) structure. Notably, the numerous process parameters of multi-pass spinning forming facilitate complex variations with strain paths. The effects of strain path on texture components and strength during the multi-pass spinning forming process were studied. However, the texture evolution mechanism was indeterminate and optimization approach for strain path was necessary to develop. A brand-new 3D boundary condition extracting method, which is capable for clarifying strain diversity of various strain path during the spinning forming, is proposed. The velocity gradients tensor with non-vanishing components captures the deformation characteristic of the spinning forming well. Based on these, a FEM-VPSC-CPFFT computational framework, which is capable of simulating the texture components during multi-pass spinning forming with difference strain path, and quantifying the relative activity frequency of each slip system, is constructed for the first time. The experimental results can further confirm the robustness of this computational framework. The results illustrate that higher relative activity frequencies of prismatic <a> and pyramidal <c + a> slip systems during CS result in more comparatively random textures compared to UDS. The strength enhancing in tangential direction with increasing relative activity frequency of the pyramidal <c + a> slip systems is attributed to the textures formed by the multi-pass CS process.