Densification, microstructure, mechanical properties, and thermal stability of high-strength Ti-modified Al–Si–Mg–Zr aluminum alloy fabricated by laser-powder bed fusion

• Ti addition promotes equiaxed grain formation via (Al,Si)3(Ti,Zr) nanoparticles, enhancing mechanical properties. • The 0.5wt% Ti alloy achieves UTS of 468 MPa and YS of 350 MPa in as-built state, outperforming traditional L-PBF Al-Si-Mg alloys. • Direct aging at 150°C further increases strength to UTS 479 MPa and YS 376 MPa, while maintaining good ductility. • Ti-modified alloy exhibits superior thermal stability at 250°C due to retained Si-rich cell boundaries, but degrades at 300°C.