Medical implants are man-made devices used to treat, heal or recover living tissues problems or deficiencies. They are made of biomaterials. To ensure durability and long-term implant, the applied biomaterial should prove high wear and corrosion resistance, suitable mechanical properties and acceptable biocompatibility. Although the progressive advancement in biomaterials, there is no record for successful permanent or long-term implant. Ni-free stainless-steel proved good biocompatibility and better mechanical properties, enhanced wear and corrosion resistance. However, the alloy still needs further investigations to enhance its tribological, mechanical and biomedical characteristics to ensure the long-term durability for orthopedic implants. For this purpose, a cost-effective and durable Fe-based (FeCrMoCB) metallic glass is proposed to be laser cladded on ASTM F2229. Metallic glasses are featured with superior wear and corrosion resistance, mechanical properties and excellent biocompatibility. To optimize the coating layer; laser power, scanning speed, substrate surface roughness, overlap percentage, and laser beam spot size were varied.
The investigations showed that the studied variables affected significantly the amorphous structure of the cladded FeCrMoCB layer which in turn affected the mechanical, tribology and corrosion properties. The results showed that an amorphous-crystalline composite structure (76% amorphous content) showed better tribological properties than high amorphous structure (87% amorphous content). The cladded FeCrMoCB metallic glass layer proved higher hardness up to five times the substrate hardness, lower wear rate – both dry and wet – up to tenth that of the substrate, significantly enhanced corrosion resistance, besides good cytocompatibility. In addition, FeCrMoCB metallic glass showed excellent bioactivity which promotes it as intermediate bioactive material for excellent osseointegration in orthopaedic implants. It is concluded that the proposed FeCrMoCB metallic glass coating has high potential for bone implants, especially for joint replacement with higher durability and bioactivity and thus less revision surgeries are needed.
By: Dr. Mahmoud Zakaria
Supervisor: Assoc. Prof. Dr. Farazila Yusof
Last Update: 27/10/2022