Investigation of residual stress characteristics and fatigue crack propagation behavior in GH4169 blisks fabricated by linear friction welding

This study established a thermal-mechanical coupling numerical simulation model for linear friction welding of GH4169 superalloy blisks using ABAQUS/Explicit and FRANC3D. A systematic analysis was conducted of the evolution laws of the temperature and residual stress fields under different process parameters during the welding process. Additionally, the effect of crack parameters on crack propagation and fatigue life under multi-axial loading was simulated. The results show that the peak temperature at the center of the friction interface is approximately 1300 °C. The stress distribution within the joint demonstrates periodic fluctuations. Axially, the friction interface experiences the maximum compressive stress. The crack parameters had a substantial effect on crack propagation characteristics. As the initial crack size increases from 0.6 mm to 1.0 mm, there is a concomitant 40.4 % reduction in fatigue life, from 75,089 cycles to 44,767 cycles. Moreover, crack propagation is highly sensitive to the crack orientation. As the crack width increases from 0.375 mm to 1 mm, the fatigue life decreased by approximately 28.2 %.