Coating a Cu plate with a Zr–Ti powder mixture using surface mechanical attrition treatment

Cu plates were coated mechanically with a mixture of Ti and Zr powders. The targets were Cu discs that replaced the end-plate of the milling vial of a SPEX 8000 shaker mill, while a small amount of Ti–Zr mixture was milled as usual. It is shown that the coatings build up via a combination of deposition, wear, deformation and defect-enhanced diffusion processes. Tests carried out using conventional and synchrotron X-ray diffraction and scanning electron microscopy revealed that the top layer of the coatings is uniform and amorphous, while the morphology of regions close to the target-coating interface is coarser.