The Role of Energy Density in Phase-Microstructure Evolution and Mechanical Properties of Ti-Zr-Cu Alloys Fabricated by Laser Powder-Bed Fusion

Abstract

Laser powder-bed fusion (L-PBF) additive manufacturing technique offers significant advantages in fabricating Ti-Zr-Cu alloys by enabling precise control over microstructure through process parameter variation. This study investigates the impact of energy density on phase formation, microstructure evolution, and mechanical properties of Ti-Zr-Cu alloys produced from blended elemental powders. By adjusting laser scan speeds to achieve different energy densities, the study reveals that high energy densities result in homogeneous β-(Ti,Zr) phases, while lower energy densities lead to incomplete melting, phase segregation, and inhomogeneous microstructures. Advanced characterisation techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD), were utilised to analyse phase composition and microstructural transformations. Vickers hardness testing demonstrated a correlation between energy density and mechanical properties, with higher energy densities improving overall material hardness. The findings offer valuable insights into optimising L-PBF process parameters for enhanced performance in additively manufactured Ti-Zr-Cu alloys, providing a pathway for advanced applications in biomedical and structural components.