Multi-Physics Modeling and Parameter Optimization for Flash Defect Control in Inertial Friction Welding of FGH98 Nickel-Based Powder Superalloy

The control of flash defects in inertial friction welding constitutes a critical challenge that limits the manufacturing accuracy of aero-engine hot-end components. This investigation employs FGH98 hollow cylinders as the subject of study, utilizing DEFORM-3D to develop a transient thermo-mechanical coupled numerical model. The research primarily explores the regulatory effects of rotational speed (800–1000 r/min) and upset pressure (2500–2900 PSI) on flash morphology defects. The results demonstrate that an overly high rotational speed (1000 r/min) causes the flash size to surpass the permissible engineering limits, machining. which not only results in material waste but also elevates the challenges associated with post-weld machining. Inadequate upset pressure (2500 PSI) leads to insufficient flash extrusion, thereby heightening the risk of incomplete bonding. Through multi-objective optimization, an optimal combination of process parameters was determined: a rotational speed of 900 r/min, an upset pressure of 2900 PSI, and a moment of inertia of 1150 lb·ft².With this parameter set, both the flash dimensions and the bend angle reside within the desirable range, and the joint strength achieves over 92% of the base metal's strength. This outcome provides key theoretical foundation and practical guidance for the manufacture of aero-engine hot-end components.