Surface modification of Ti6Al4V alloy via advanced coatings: Mechanical, tribological, corrosion, wetting, and biocompatibility studies

Abstract

Titanium alloys play a prominent role as metallic biomaterials in the biomedical sector, particularly for implant applications. Various types of Ti alloys are suitable for medical treatment, including Ti6Al4V (Ti64) alloys, which are extensively utilized in biomedical implant materials. This preference was attributed to their commendable strength, excellent corrosion and wear resistance, and satisfactory biocompatibility. Nonetheless, implants produced through diverse additive manufacturing (AM) methods or commercially available methods face performance-related challenges, including mechanical, wear resistance, corrosion resistance, wettability, and biocompatibility. To address these limitations, researchers have actively sought ways to enhance the implant performance. An effective approach to overcoming these challenges involves surface modification using advanced coatings. Therefore, this work provides a comprehensive review of various surface coating materials and techniques employed to enhance the mechanical properties, wear resistance, corrosion resistance, wettability, and biocompatibility of titanium alloys for biomedical applications. This review encompasses an array of coating materials, including metal nitrides (MNs), diamond-like carbon (DLC), high-entropy alloys (HEA), metal oxides (MO), and polymer–metal oxide (P-MO) composites. It offers detailed insights into the operational bio-mechanisms of various coatings, thoroughly discusses how and which type of coatings enhance biocompatibility, and provides valuable insights for advancing the field.