Temperature-dependent crack behavior and microstructure evolution mechanisms in hot stamped Ti65 titanium alloy sheets

High-precision manufacturing and effective defect control in hot stamping of thin-walled titanium alloy components present significant engineering challenges. Frequent issues like uneven thickness, shape distortion, and cracking necessitate in-depth analysis of their underlying mechanisms. This study employed Global Schmid Factor and Idealized Grain Microstructure Analysis models to investigate the hot stamping behavior of 2 mm-thick novel high-temperature Ti65 alloy sheets with initial transverse texture at 900 °C and 1000 °C. Results showed that within the 900–1000 °C range, Ti65 alloy sheet formability improved with increasing temperature. Fracture locations after stamping at 900 °C and 1000 °C exhibited temperature dependence. This was attributed to temperature significantly modulating in-plane tensile uniformity and thinning capability by influencing the uniformity and strain distribution of internal plastic deformation, highlighting the crucial role of inherent material anisotropy in hot stamping. Microstructural analysis confirmed that during high-temperature forming, microstructure and texture evolution were governed by phase transformation-deformation interaction, which promoted the activation of α-phase prismatic slip systems influenced by the initial texture. This work provided a theoretical basis for optimizing Ti65 hot stamping parameters, suppressing forming defects, and enhancing material performance and production quality.