Effect of welding speed on residual stress in 205C aluminum alloy via CMT+P WAAM

Welding speed is a critical parameter in CMT+P-based WAAM of 205C aluminum alloy, which is used in aerospace structures such as the XX-BQ missile casing. This study investigates how welding speed affects residual stress and warping in deposited components. Four welding speeds were tested under otherwise constant parameters. Warping was measured via 3D laser scanning, and residual stress was evaluated using X-ray and LCR ultrasonic methods. Results indicate that welding speed governs heat input per unit length and significantly influences the magnitude, symmetry, and variability of residual stress. Warping behavior closely follows the stress evolution. At 10.0 mm/s, both residual stress and warping reach their minimums, with the lowest warping symmetry index (WSI), indicating the most balanced thermo-mechanical response. These findings establish the linkage between welding speed, heat input, and structural distortion, and guide stress mitigation in high-integrity WAAM aluminum alloy components.