Comparison of the wear and frictional properties of Cu matrix composites prepared by pulsed electric current sintering; pp. 62–74

Abstract

Wear performance of Cu matrix composites prepared by pulsed electric current sintering (PECS) was evaluated by using non-lubricated sliding tests. The studied materials contained cuprite (Cu2O), alumina (Al2O3), titaniumdiboride (TiB2) or diamond dispersoids in a coarse-grained Cu (c-Cu), submicron-grained Cu (sm-Cu), or nano-grained Cu (nCu) matrix. PECS compacted matrix materials were used as references. The ball-on-flat tests showed strong dependence of the coefficient of friction (CoF), wear rate and wear mechanism on the counter ball material. Cr-steel balls led to high CoF (0.71–1.01) and high wear rate (1.3 x 10–5–5.7 x 10–3 mm3/Nm) depending on the test material and its reactivity with the counterpart. Cu-Cu2O yielded to lowest CoF and wear rate with a presence of oxidational and abrasive wear, whereas, Cu-Al2O3 and Cu-diamond suffered of adhesive wear leading to much higher wear rates. On the other hand, alumina ceramic counterpart led to a considerably lower CoF (0.39–0.92) and wear rate (1.4 x 10–7–6.1 x 10–6 [mm3/Nm]), and the test materials showed oxidational wear and material pile-up. Of the composites, Cu-diamond showed the lowest wear rate and Cu-Cu2O and Cu-diamond (5 nm) showed the lowest CoF against alumina. It is believed that the present work gives new insights for materials selection, e.g., in electronic connector parts.