Crucial Factors Influencing Mechanical and Thermal Properties of Cold-Sprayed CuCrZr Composite Coating

Cold spray was employed to apply CuCrZr-based composite coatings onto CuCrZr substrates, aiming to enhance both their mechanical and thermal properties. A comparison was drawn between wear-resistant SiC and high thermal conductivity AlN reinforcements in terms of shear strength, tribological behavior, and thermal conductivity. Results show that the 30vol.% AlN/CuCrZr and 45vol.% SiC/CuCrZr coatings have similar grain structures, ceramic content and particle size distribution, but a distinct mean free path of the ceramics. The 30vol.% AlN/CuCrZr coating exhibits superior hardness and shear strength compared to the 45vol.% SiC/CuCrZr coating, attributed to the greater dispersion strengthening effect arising from the closely spaced AlN particles while the sparse distribution of SiC particles facilitates formation of the CuO lubricating film, resulting in the better wear resistance of the SiC/CuCrZr coating. Finally, the 30vol.% AlN/CuCrZr coating demonstrates superior thermal performance due to the higher thermal conductivity inherent in AlN ceramic. Therefore, the inherent thermal conductivity and distribution of the ceramic particles could be crucial factors in achieving comprehensive thermal and wear performance for the CuCrZr composite coating.