Mechanical Behavior of Aluminum Matrix Composites Reinforced with Nanoscale Carbon Nanotubes and Silicon Carbide

Abstract

Lightweight aluminum (Al) matrix composites reinforced with carbon nanotubes (CNTs) and nanoscale silicon carbide (SiC) were fabricated using high-energy attrition milling, nitridation-induced self-forming consolidation (NISFAC), and hot pressing to improve mechanical performance through CNT/SiC hybrid reinforcement. Attrition milling refined the composite powders and promoted the incorporation of CNTs and SiC particles into the Al matrix, whereas NISFAC and hot pressing enabled near-full densification and effective interparticle bonding. Among the investigated compositions, Al/5CNT/3SiC showed the best mechanical performance, with a hardness of 197 HV, compressive yield strength of 432 MPa, compressive strength of 756 MPa, and Young’s modulus of 110 GPa. These improvements are attributed to the combined effects of load transfer, thermal-mismatch-induced dislocation strengthening, Orowan strengthening, and grain-boundary strengthening. Compared with values reported in the literature, the present composites showed competitive mechanical properties despite their relatively low reinforcement content. These findings indicate that CNT/SiC hybrid reinforcement combined with NISFAC and hot pressing is an effective route for producing dense, high-strength Al matrix composites.