Microstructure, mechanical properties and tribocorrosion testing of selective laser melted ZTM35E alloy

In this investigation, a ZTM35E alloy was successfully synthesized by Selective Laser Melting (SLM) to examine its microstructure, mechanical efficiency, and tribocorrosion performance. The ZTM35E alloy showed a refined microstructure comprise of α′ martensitic structure with α-Ti spots aligned along the build direction due to directional solidification. It possesses a substantially lower elastic modulus (73 GPa) than Ti6Al4V (110 GPa) and is closer to the modulus of human bone, offering enhanced biomechanic as compatibility via lowering stress shielding. Additionally, The ZTM35E alloy also revealed a reasonably comparable hardness and tensile strength to Ti6Al4V. Electrochemical results in simulated bodily fluids revealed a corrosion current density of 7.5 × 10⁻⁷ A/cm² for ZTM35E, greater than Ti6Al4V (∼1 × 10⁻⁷ A/cm²), nevertheless remaining within acceptable limits for biomedical usage. With respect to tribocorrosion investigates at open circuit potential, the alloy demonstrated a fairly low specific wear rate (0.79 × 10⁻⁴ mm³/N·m) compared to Ti6Al4V (1.39 × 10⁻⁴ mm³/N·m) at high-load conditions. These outcomes suggest ZTM35E's potential as a safe and more bone-compatible candidate to Ti6Al4V for load-bearing medical implants made using additive manufacturing.