Synchrotron Characterisation of Ultra-Fine Grain TiB2/Al-Cu Composite Fabricated by Laser Powder Bed Fusion

Abstract Isotropy in microstructure and mechanical properties remains a challenge for laser powder bed fusion (LPBF) processed materials due to the epitaxial growth rapid cooling LPBF. In this study, high-strength TiB 2 /Al-Cu composite with random texture was successfully fabricated by using pre-doped powder. A series of advanced characterisation techniques, including synchrotron X-ray tomography, correlative focussed ion beam–scanning electron microscopy (FIB-SEM), scanning transmission (STEM), situ diffraction, were applied investigate defects as-fabricated across multiple length scales. The study showed ultra-fine grains an average grain size about 0.86 μm, formed condition solidification particles promoting heterogeneous nucleation. yield strength total elongation 317 MPa 10%, respectively. contributions fine grains, solid solutions, dislocations, particles, Guinier–Preston (GP) zones calculated. Failure found be initiated from largest lack-of-fusion pore, as revealed tomography during tensile loading. diffraction used characterise lattice strain evolution loading, providing important data development crystal-plasticity models.