Engineering functionally graded Cu–Ti2SnC composites for enhanced mechanical and tribological performance

Abstract

This study investigates the fabrication of Cu–titanium tin carbide (Ti 2 SnC) functionally graded composites (FGCs) through a novel deformation-assisted manufacturing (DAM) process and evaluates their microstructural evolution, mechanical performance, tribological behavior, and electrical conductivity. A five-layer graded architecture containing 0–20 wt.% Ti 2 SnC was successfully consolidated under solid-state conditions using simultaneous compressive and shear deformation. Finite element modeling was employed to analyze the thermo-mechanical conditions governing grain refinement during processing. Microstructural analysis revealed fully consolidated, defect-free layers with strong interfacial bonding and a pronounced grain refinement from 9.2 ± 0.5 μm in the unreinforced copper layer to 1.3 ± 0.3 μm in the 20 wt.% Ti 2 SnC layer. Consequently, hardness increased from 70.3 ± 2.7 HV to 192.6 ± 6.2 HV, corresponding to a 174% improvement. Tribological testing demonstrated a substantial reduction in friction coefficient from 0.56 to 0.36 and a decrease in wear rate from 6.9 ± 0.2 to 4.7 ± 0.5 μg m -1 , yielding approximately 30% higher wear resistance and an estimated 1.5-fold increase in service life. Tensile strength increased from 221 ± 4 MPa to 316 ± 6 MPa, while yield strength improved from 161 ± 3 MPa to 223 ± 5 MPa. Despite these gains, the composite retained a reasonable elongation of 14 ± 1%. Electrical conductivity remained relatively high, decreasing moderately from 95.4 ± 1.1% International Annealed Copper Standard (IACS) to 82.1 ± 1.5% IACS. The results demonstrate that DAM enables the development of multifunctional Cu-based graded composites with an excellent balance of strength, wear resistance, conductivity, and sustainability-oriented performance.