Improving the mechanical and tribological properties of Cu matrix composites by doping a Mo2BC ceramic

Abstract

Cu matrix composites (CMCs) are widely employed for tribological applications such as in sliding bearings and electrical contact fields. However, the Cu matrix needs to be modified to improve its mechanical and tribological properties. In this study, CMCs reinforced with Mo2BC ceramic particles (10–30wt.%) are prepared via the spark plasma sintering (SPS) route method. In comparison with the plain Cu sample, when the content of the Mo2BC particles increased to 30wt.%, the Vickers hardness, yield strength, and tensile strength of CMCs increased by 196%, 157%, and 588%, respectively. Fine grain and load transfer strengthening mechanism are considered the main strengthening mechanism. Introducing the Mo2BC ceramic effectively reduces friction and wear as well as the frictional noise vibration of CMCs. Incorporating Mo2BC ceramic into the Cu matrix can elevate the load-bearing ability, inhibiting mechanical and adhesive wear. In addition, the composite exhibits superior friction and wear properties as the content of Mo2BC ceramic increases gradually up to 30wt. %, where the friction coefficient and wear rate are as low as 0.35 and 3.25 × 10−6 mm3/Nm, respectively. A layer of tribo-film containing Fe2O3 derived from the counterparts and induced by the tribo-oxidation reaction can provide a lubricating effect. Considering the superior mechanical and tribological properties, the as-prepared CMCs could be an attractive alternative material for sliding bearing fields.