Characterization of Residual Stresses in Al and Al-Al₂O₃ Cold Sprayed Coatings

In the present work, pure Al and Al-Al₂O₃ composite coatings are deposited by cold spraying while measuring in-flight particle velocities. Residual stresses, evaluated using the Almen curvature method, X-day diffraction, and modified layer removal, are correlated with particle velocity, coating thickness, and alumina content. Peening stresses due to plastic deformation were estimated to be less than 100 MPa and are shown to be nearly constant through the thickness of the coatings.