Investigation of microstructure, mechanical properties, and biocorrosion behavior of Ti1.5ZrTa0.5Nb0.5W0.5 refractory high-entropy alloy film doped with Ag nanoparticles

Even though metallic biomaterials have long been utilized as the key materials in biomedical applications due to their exceptional mechanical properties, corrosion and bacterial infection problems place a limit on their prolonged clinical applications. In order to overcome such problems, surface modification of the implants via exerting a durable and protective coating containing antibacterial agents is crucial. In this study, undoped and Ag-doped Ti1.5ZrTa0.5Nb0.5W0.5 refractory high-entropy alloy (RHEA) films with a thickness of 1.10 μm were deposited on Ti6Al4V alloys through RF magnetron sputtering technique. The influence of the deposited film and embedding Ag nanoparticles on microstructure, mechanical properties, and electrochemical behavior was investigated. The microstructural findings revealed an amorphous structure with cauliflower-like morphology for deposited films. Coated specimens showed a significant improvement in surface mechanical properties such as elastic modulus and hardness. Doping Ag nanoparticles in the deposited film increased the roughness and contact angle of the specimens due to the evolution of Ag nanoparticles. Furthermore, electrochemical investigations revealed that undoped and Ag-doped deposited films remarkably improved the corrosion resistance of uncoated substrate; after the films deposition process, the corrosion rate of the specimens decreased 2.3 to 2.8 orders of magnitude compared to the uncoated substrate. Also, embedding Ag nanoparticles notably increased the polarization resistance of deposited films.