Effect of Addition of Er-TiB2 Dual-Phase Nanoparticles on Strength-Ductility of Al-Mn-Mg-Sc-Zr Alloy Prepared by Laser Powder Bed Fusion

Abstract:

A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion (LPBF) by leveraging the unique advantages of Er and TiB₂. Spherical powders of 0.5wt% Er-1wt% TiB₂/Al-Mn-Mg-Sc-Zr nanocomposite were prepared using vacuum homogenization technique, and the density of samples prepared through the LPBF process reached 99.8%. The strengthening and toughening mechanisms of Er-TiB₂ were investigated. The results show that Al₃Er diffraction peaks are detected by X-ray diffraction analysis, and texture strength decreases according to electron backscatter diffraction results. The added Er and TiB₂ nano-reinforcing phases act as heterogeneous nucleation sites during the LPBF forming process, hindering grain growth and effectively refining the grains. After incorporating the Er-TiB₂ dual-phase nano-reinforcing phases, the tensile strength and elongation at break of the LPBF-deposited samples reach 550 MPa and 18.7%, which are 13.4% and 26.4% higher than those of the matrix material, respectively.