Refractory multi-principal element alloys (RMPEAs) have become one of the most promising candidates for hightemperature structural and hard protective coating materials due to their high strength and thermal stability. In present work, Mo-Ta-W RMPEA thin hard films were successfully fabricated via direct current (DC) multi-target magnetron co-sputtering technology. The phase structure, microstructure, surface roughness and mechanical properties of the Mo-Ta-W RMPEA thin films were investigated. The as-deposited Mo-Ta-W RMPEA thin films with a wide range of compositions presented a single body-centered cubic (BCC) solid solution structure. Nanocrystalline with average grain size of 10- 15 nm (estimated according to the Scherrer equation) was formed in these films. The surface morphology of the films exhibited the flake-like shape with small roughness value of Ra = 4- 8 nm, and cross-sectional structure revealed columnar dendrite. The Mo-Ta-W RMPEA thin films displayed superior mechanical properties with the hardness of ~20 GPa and the elastic modulus of beyond 270 GPa. The Mo-Ta-W alloy thin films had the high H/E and H3/E2 values, indicating that the alloy thin films should have excellent wear resistance. Hence, these Mo-Ta-W RMPEA thin films can be considered as candidates for hard protective coating applications.
Key words
Refractory multi -principal element alloy thin film/Multi-target magnetron co-sputtering/Phase structure/Microstructure/Mechanical properties/HIGH-ENTROPY ALLOY/NANOSTRUCTURED NITRIDE FILMS/THERMAL-STABILITY/ELECTRICAL-PROPERTIES/SOLID-SOLUTION/SINGLE-PHASE/TEMPERATURE/BARRIER/RESISTANCE/STRENGTH
NSTL
Elsevier