Tailoring Strength, Conductivity, and Tribological Performance in Cu–2 wt.% (Fe-1 wt.% C) Composites through Deformation-Driven Processing

Abstract

Deformation-driven metallurgy (DDM) was employed to fabricate Cu–2 wt.% (Fe–1 wt.% C) composites in order to examine the influence of processing conditions on microstructure, mechanical behavior, tribological performance, and electrical conductivity. Consolidation was performed using rotating punch speeds of 800, 1600, and 2400 rpm, producing fully dense composites within approximately 15 s through severe plastic deformation and frictional heating. The average grain size of the copper matrix increased from 5.6 ± 1.2 μm at 800 rpm to 8.7 ± 1.4 μm at 1600 rpm and 11.7 ± 1.2 μm at 2400 rpm due to enhanced dynamic recrystallization and thermally driven grain growth. Mechanical results showed that the composite processed at 800 rpm exhibited the highest hardness and strength, reaching 159.1 ± 5.1 HV 0 . 1 and 334.1 ± 11.1 MPa, respectively. Increasing the rotational speed to 2400 rpm reduced hardness to 111.2 ± 7.6 HV 0 . 1 and tensile strength to 304.1 ± 10.2 MPa, mainly due to grain coarsening and less uniform particle distribution. In contrast, elongation increased from 24.4 ± 1.3% to 28.7 ± 1.2% with increasing rotational speed, indicating improved matrix plasticity at higher temperatures. Tribological measurements revealed that both the coefficient of friction and wear rate increased with rotational speed, accompanied by a transition from predominantly abrasive wear at 800 rpm to adhesive wear at 2400 rpm. Electrical conductivity remained high but gradually decreased from 94.8 ± 0.5 to 89.2 ± 0.5 % IACS as rotational speed increased.