Comparative Assessment of SS316L vs Hydroxyapatite (HAp) Composites for Biomedical Implant Applications

Abstract

This study presents a comparative assessment between SS316L stainless steel and hydroxyapatite (HAp)-based composites derived from bovine bone waste for sustainable biomedical implant applications. The analysis focuses on key physical and mechanical properties, including density, hardness, porosity, and compressive strength. SS316L exhibits high density (~7.9 g·cm⁻³), hardness (~150–220 HV), and compressive strength exceeding 500 MPa, making it suitable for load-bearing applications. In contrast, HAp-based composites show lower density (~2.8–3.2 g·cm⁻³), hardness (~40–75 HV), compressive strength (~50–200 MPa), and controlled porosity (~20–30%), which are advantageous for bone integration and bioactivity. Rather than serving as a direct replacement, HAp-based composites are better positioned as complementary biomaterials, particularly in coatings or hybrid implant systems. This study highlights the potential of waste-derived HAp composites as a sustainable material solution in biomedical engineering.