Enhancement of Bioactivity of Zr-50Ti Alloys through Sulfuric Acid Treatment Followed by Modified Simulated Body Fluid Treatment

Zirconium-titanium (Zr-Ti) alloys are known for their superior strength, corrosion resistance, and biocompatibility, making them promising biomaterials. Among these, Zr-50Ti alloys exhibit a lower elastic modulus and reduced magnetic susceptibility compared to pure titanium (Ti), which diminishes stress shielding and minimizes interference during medical diagnostics. Despite these advantages, Zr-50Ti alloys lack inherent bioactivity, necessitating surface modification to enhance their ability to bond with bone. This study aimed to impart bioactivity to Zr-50Ti alloys through sulfuric acid treatment to create micropores, followed by treatment in a modified simulated body fluid (m-SBF) under moderate conditions (36.5 °C, pH 7.40). The bioactivity of the treated alloys was evaluated by soaking in simulated body fluid (SBF) for 1, 3, and 7 days. The results demonstrated that the sulfuric acid treatment significantly enhanced the calcium phosphate precipitation ability of Zr-50Ti alloys in m-SBF, leading to successful precipitation. This approach under mild conditions suggests the potential for further testing on materials suitable for biological conditions without additional restrictions.