Effects of SLM Process Parameters and TiC Nanoparticles on the Microstructure and Mechanical Properties of AlSi10Mg

AlSi10Mg alloy reinforced with TiC nanoparticles was manufactured using the selective laser melting (SLM) process. The study aimed to investigate the influence of laser process parameters on density, microhardness, and surface roughness using Archimedes' principle, Vickers micro-indentation hardness, and 2D surface roughness profiling. The effects of TiC nanoparticles on microstructure and mechanical properties were analyzed using optical microscopy (OM), scanning electron microscopy (SEM), x-ray diffraction (XRD), hardness and tensile testing, and digital image correlation (DIC). Near fully dense parts were achieved using a laser energy density (LED) corresponding to 0.36 J/mm. The highest microhardness values obtained were 133 HV_0.1 for samples produced with a 30 µm layer thickness and 130 HV_0.1 with a 60 µm layer thickness. Specimens produced with 30-µm layers also exhibited superior surface quality. The high laser absorptivity of TiC promoted the dissolution of nano-Ti, enriching the aluminum matrix and forming secondary phases that influenced the alloy's mechanical properties. The presence of numerous micropores and deep dimples indicated ductile fracture, attributed to weaker metallurgical joints, and unmelted powder particles acting as stress concentrators, thereby accelerating rupture.