How are residual stresses managed in aerospace component manufacturing?

Residual stresses from manufacturing can affect distortion, fatigue, and corrosion. Sources: Quenching (thermal gradient), Machining (surface stresses), Welding (shrinkage), Cold working, and Casting solidification. Problems: Part distortion during machining (potato-chipping), Reduced fatigue life if tensile residual stress, Stress corrosion cracking susceptibility, and Dimensional instability. Measurement: X-ray diffraction (surface stress), Hole drilling (subsurface profile), Contour method (bulk), and Neutron diffraction (thick sections). Mitigation: Material: Controlled quench (uphill quench, polymer quench), Pre-stretching after quench (relief). Process: Stress relief heat treatment, Progressive machining strategies, and Cryogenic treatment. Design: Account for redistribution when machining, Avoid thin sections from thick material. Beneficial residual stress: Shot peening (surface compression), Cold expansion of holes (bushing/split sleeve), and Laser shock peening. Residual stress analysis required for critical components. Specifications may define stress limits.