Research on the Microstructure Characterization and Fatigue Behavior of Nickel-Based Superalloy Subjected to Short-Arc and Milling Composite Processing

• Short-arc machining combined with precision milling enables efficient and high-precision processing of nickel-based superalloys, addressing challenges of traditional methods. • The recast layer formed during short-arc machining exhibits an 85.5% reduction in grain size and a heat-affected layer depth exceeding 400 μm, significantly altering surface microstructure. • Fatigue life correlates strongly with residual stress, grain orientation spread, and geometrically necessary dislocations, providing a basis for process optimization. • Optimal machining parameters (larger axial depth of cut, lower feed per tooth) enhance fatigue life, offering practical guidance for aerospace component manufacturing.