Sliding wear of Ai-Fe-Ce-SiC composites lubricated with several typical additives

Increasing quantities of aluminum matrix composites (AMCs) are being used to replace conventional materials in many weight-critical fields for energy savings. More efforts are employed to improve the antiscuffing and antiwear properties of AMCs. In this paper, silicon carbide (SiC) whisker-reinforced Al-Fe-Ce (AFC) aluminum matrix composites were fabricated by a powder metallurgy method. A 440C stainless steel ball was run against the composite in a small amplitude reciprocal sliding tester at applied loads of 40 to 200 N and an average speed of 0.045 ms⁻¹ at ambient conditions. The lubricant was a liquid paraffin (LP) base oil without and with 3 wt% tricresyl phosphate (TCP), sulphurized olefin (SO) or chlorinated paraffin (CP). The composites exhibited obvious antiwear properties. The Auger electron spectroscopy and X-ray pholoelectron spectroscopy analysis showed that the iron of the composite reacted with TCP, SO and CP additives and produced antiwear films on the worn surfaces. Scanning electron microscope and optical microscopy were used to analyze the worn morphologies. The main wear mechanisms observed were ploughing and tribochemical wear when additives were used. Adhesive wear (at low loads) and severe ploughing (at high loads) were found when additives were not used.