Effect of Process Parameters on the Microstructure and Properties of Ti15Zr5Cu Alloy Fabricated via Selective Laser Melting

Abstract

Ti-Zr-Cu alloy has garnered significant attention in the field of dental implants due to its excellent biocompatibility, antibacterial properties, and potentially controllable mechanical properties. However, two critical challenges remain in the selective laser melting (SLM) fabrication of Ti-Zr-Cu alloy: First, the high thermal conductivity of the Cu element tends to destabilize the solidification behavior of the molten pool, leading to uncontrollable pore defect evolution; Second, the influence of process parameters on the synergistic effects of zirconium solution strengthening and copper precipitation strengthening is not well understood, hindering precise control over the material's mechanical properties. To address these issues, this study systematically elucidates the quantitative impact of energy input on the defect formation mechanisms and strengthening effects in the SLM processing of Ti15Zr5Cu alloy. By optimizing laser power (120–200 W) and scanning speed (450–1200 mm/s) through a full-factor experimental design, we comprehensively analyze the effects of energy input on defect morphology, microstructure evolution, and mechanical performance. The results demonstrate that as energy density decreases, defect types transition from spherical pores to irregular pores, significantly influencing mechanical properties. Based on the defect evolution trends, three distinct energy density regions are identified: the high-energy region, the low-energy region, and the transition region. Under the optimal processing conditions of a laser power of 180 W and a scanning speed of 1200 mm/s, the Ti15Zr5Cu alloy exhibits a relative density of 99.998%, a tensile strength of 1490 ± 11 MPa, and an elongation at break of 6.0% ± 0.5%. These properties ensure that the material satisfies the stringent requirements for high strength in narrow-diameter implants used in the maxilloanterior region. This study provides theoretical and experimental support for the process-property optimization of Ti-Zr-Cu alloys in additive manufacturing and promotes their application in the fabrication of high-performance, antibacterial dental implants.