Effect of heat treatment on the inherent anisotropy of cold sprayed copper deposits

In the present investigation, the effect of post-spray heat treatment (PSHT) on the microstructural and mechanical anisotropies of cold spray (CS) Cu deposits was investigated. The electron back-scattered diffraction and nanoindentation techniques were employed to characterize the microstructure and micromechanical properties in the cross-sectional (v-face) and parallel direction (p-face) to the surface following PSHT. Tensile tests were performed at various loading angles to identify the effect of PSHT on the in-plane tensile anisotropic behavior. It is revealed that microstructural anisotropy exists in both the as-sprayed and annealed CS deposits. And PSHT can effectively reduce the micromechanical anisotropy between the v-face and p-face. Tensile results show that the strong anisotropy of in-plane tensile strength can be moderated with PSHT. However, its effect on elongation anisotropy is quite limited, and the anisotropy is greatly increased at 700 degrees C. The existence of parallel multiple passes during CS remains the main factor hampering the further modification of the inherent in-plane tensile anisotropy especially elongation anisotropy.