INVESTIGATION OF THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SAMPLES WITH A TPMS STRUCTURE MADE OF TI-10TA-2NB-2ZR ALLOY OBTAINED BY SELECTIVE LASER MELTING
The microstructure, phase composition, and mechanical properties of dense and porous specimens made of biocompatible β-titanium alloy Ti-10Ta-2Nb-2Zr produced by selective laser melting (SLM) were investigated. An optimal processing window (volumetric energy density of 61.7−94.1 J/mm3) was established, yielding a relative density of up to 99.92%. The as-built condition exhibited a fine acicular α′-martensitic structure, which provided high strength (ultimate tensile strength of 642 MPa, yield strength of 552 MPa) together with a reduced elastic modulus of 88 GPa. Annealing at 900 °C resulted in recrystallization and formation of an equilibrium lamellar α+β structure, further decreasing the elastic modulus to 85 GPa while maintaining sufficient ductility (elongation ~20%). To mimic trabecular bone, triply periodic minimal surface (TPMS) structures (Schwartz, Gyroid, Split) with 50% porosity were fabricated. Their effective elastic modulus (9.1−9.6 GPa) is comparable to that of bone tissue, thus addressing the stress shielding issue. The obtained results demonstrate the high potential of the Ti-10Ta-2Nb-2Zr alloy and SLM technology for manufacturing personalized orthopedic implants with improved biomechanical compatibility.