Customization and prospects of friction stir processing for improving the biomedical properties of metallic implants for orthopedic applications

The significance of biomedical applications of friction stir processing (FSP) is best emphasized by their prospect utilization in improving the biomedical properties of metallic implants for orthopedic applications. FSP facilitates the stable incorporation of functional elements into implant materials for tailored modification of performance, preserves the advantageous properties of the matrix while mitigates inherent weaknesses, and provides a customized solution to multifaceted challenges that affects the long-term functionality of implants. This remarkable advantage in reinforcing properties gives FSP the ability to improve biomedical properties in metallic implants for orthopedic applications. This review (i) provides an overview of the current status and issues of metallic implants for orthopedic applications, with a special attention to the potential of FSP to address the performance decay commonly encountered by implant materials. (ii) details the principles for the development of FSP process parameters to the performation modification of implant materials, (iii) introduces the customized design of implant materials by FSP (including magnesium alloys, titanium alloys and other alloys, as well as their physico-mechanical properties and implant application), and (iv) highlights the influence of FSP on the biological functionality of implant materials. Also explored are the main challenges and perspectives in developing FSMed metallic implants for orthopedic applications.