Microstructure and mechanical properties of novel SiC-TiC/Al-Mg-Sc-Zr composites prepared by selective laser melting

• SiC-TiC particle reinforcement achieves near-full density (up to 100%) in SLM-fabricated Al-Mg-Sc-Zr composites, significantly improving forming quality. • In-situ formation of acicular Al4SiC4 bands via interfacial reaction between SiC and Al matrix, while TiC forms a semi-coherent interface with strong bonding. • TiC nanoparticles exert grain-boundary pinning, refining equiaxial grains and preventing transition to columnar structure. • The composite achieves UTS ~394 MPa, YS ~262 MPa, EL ~8.2%, and elastic modulus ~86 GPa, addressing the low elastic modulus limitation of SLMed aluminum alloys.