Developing a new laser cladded FeCrMoCB metallic glass layer on nickel-free stainless-steel as a potential superior wear-resistant coating for joint replacement implants

Biomedical implants are made of biomaterials such as titanium, cobalt-based alloys or stainless-steel depending on which is the most suitable. However, metallic alloys have failed to prove high wear resistance alongside acceptable biocompatibility. Recently, metallic glasses (MG) have attracted more attention for joint replacement implants due to their superior wear resistance and acceptable biocompatibility, however, they are brittle material and constrained in size to few centimeters. Therefore, MG coating layer on ductile-core metallic alloy like stainless-steel would overcome the drawbacks of MG and develop a well-functioning joint replacement implant. In this research, FeCrMoCB MG is laser cladded on nickel-free stainless steel using three levels of specific energy, scanning speed, spot size and overlap percentage to develop different amorphous-crystalline composite structures. The cladded samples showed superior wear resistance in both dry and Ringer's solution conditions (up to 270 times that of the substrate) demonstrating comparable wear rate with common metallic biomaterials that leads to promoted durability. Furthermore, the cell-culture test applied to FeCrMoCB coating layer and substrate showed good cell morphology and growth on both surfaces indicating an acceptable cytocompatibility of both coating layer and substrate.