Impact of Sintering Duration on the Mechanical and Bioactive Properties of Pure Ti, Ti-Al Alloy, and Ti-Al-HAp Composite for Biomedical Applications

Commercially pure titanium is widely used in biomedical applications due to its excellent biocompatibility, although its bioinert nature limits osseointegration.This study incorporated hydroxyapatite (HAp) to enhance bioactivity, and aluminum (Al) was added to improve mechanical performance.The effect of sintering time on the relative density, compressive strength, microhardness, and bioactivity of CP-Ti, Ti-6%Al, and Ti-6%Al-2%HAp composites was investigated.The samples were fabricated via powder metallurgy and sintered at 1300 for 60, 90, and 120 minutes.Results indicated that increasing the sintering time improved all evaluated properties.At 120 minutes, relative densities reached 91.72%, 92.78%, and 93.31%, while compressive strengths were 511 MPa, 492 MPa, and 476 MPa for CP-Ti, Ti-6%Al, and Ti-6%Al-2%HAp, respectively.Microhardness values also increased, reaching 379 HV, 351 HV, and 298 HV.XRD analysis identified the formation of bioactive phases, including TiPO, TiO, AlTi, NaTiO, CaTiPO, and CaTiO.The MTT assay confirmed low cytotoxicity (13.3%) in three days.AAS results showed minimal Ti (0.912 ppm) ions and no Al ions release in 14 days.These findings highlight the significant role of sintering time in enhancing the mechanical and bioactive performance of Ti-based composites for biomedical applications.