Stress Profiling in Cold-Spray Coatings by Different Experimental Techniques: Neutron Diffraction, X-ray Diffraction and Slitting Method

Abstract

The residual stress profiles in Cu and Al coatings sprayed using kinetic metallization to thickness of ~2 mm have been studied. Due to specific parameters of the cold spray process and particular combination of materials of coatings and substrates the residual stresses are low, with magnitudes of the order of a few tens of MPa. This poses challenges accuracy and resolution when measuring through-thickness stress distributions. Three experimental techniques - neutron diffraction, x-ray diffraction and a slitting method - were used to measure through-thickness stress distributions in the substrate-coating systems. All three techniques demonstrated acceptable accuracy and resolutions suitable for analyzing stress profiles. Advantages and disadvantages of each technique are discussed.