XRD-Based Residual Stress Measurement of Cold Sprayed Ni Coating

A GRCop-42 cylinder was produced by North American Manufacturing Pros using laser powder bed fusion to measure the residual stress at a bimetallic joint with NASA HR-1. Pure Ni was applied by ASB Industries as a diffusion barrier between the GRCop-42 and NASA HR-1 using cold spray. Residual stress measurements of the Ni layer in the as-cold sprayed and heat-treated conditions were collected on the top surface of the coating using x-ray diffraction with Co Kα radiation and the Sin²ψ method at multiple phi (φ) angles. Biaxial stress values and rotation angles between the original sample axes (φ = 0° direction) and the principal axes were calculated at three equally spaced locations around the perimeter of the cylindrical part. The stress measurements were plotted at their respective positions around a circle, and with the rotation angles for each, to reveal rotational symmetry in the tension and compression of the coating.