Wear mechanism for spray deposited Al-Si/SiC_p composites under dry sliding condition

TENG Jie(滕杰), LI Hua-pei(李华培), CHEN Gang(陈刚)

(College of Materials Science and engineering, Hunan University, Changsha 410082, China)

Abstract:Al-Si/15%SiC_p (volume fraction) composites with different silicon contents were fabricated by spray deposition technique, and typical microstructures of these composites were studied by optical microscopy (OM). Dry sliding wear tests were carried out using a block-on-ring wear machine to investigate the effect of applied load range of 10-220 N on the wear and friction behavior of these composites sliding against SAE 52100 grade bearing steel. Scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDAX) were utilized to examine the morphologies of the worn surfaces in order to observe the wear characteristics and investigate the wear mechanism. The results show that the wear behavior of these composites is dependent on the silicon content in the matrix alloy and the applied load. Al-Si/15%SiC_p composites with higher silicon content exhibit better wear resistance in the applied load range. Under lower loads, the major wear mechanisms are oxidation wear and abrasive wear for all tested composites. Under higher loads, severe adhesive wear becomes the main wear mechanisms for Al-7Si/15%SiC_p and Al-13Si/15%SiC_p composites, while Al-20Si/15%SiC_p presents a compound wear mechanism, consisting of oxidation, abrasive wear and adhesion wear.

Key words:dry sliding wear; wear mechanism; Al-Si/SiC_p composites; spray deposition