A Method for Residual Stress Estimation of AZ31 under Cold Spray Coating

Surface treatment has become an effective method to improve corrosion resistance of magnesium alloys which are the lightest commercial structural alloys with superior specific strength and stiffness. Low pressure cold spraying, a novel solid state spraying process, has been used to locally deposit aluminum on AZ31 in order to enhance general and galvanic corrosion of magnesium. This study is aimed at numerical estimation of the residual stress profile due to cold spray coating using FEM. The impact of particles on the substrate is modelled in Abaqus Explicit. The challenge of AZ31 simulations is the intrinsic yield asymmetry and anisotropy which results different behaviour of the material along different direction both in tension and compression. On the other hand, there is no precise material model capable of considering the yield asymmetry and anisotropy experienced by AZ31 in Abaqus. This paper studies to study the effect of anisotropy of the AZ31 on residual stress. The results are compared with experimental X-Ray diffraction measurements of the residual stress on the specimens. This study will suggest the possibility of using an isotropic model in one of the direction of AZ31 in order to estimate the profile of residual stress.