Investigation of Friction and Wear Behavior of Cast Aluminum Alloy Piston Skirt with Graphite Coating Using a Designed Piston Skirt Test Apparatus

A piston skirt friction and wear apparatus that simulates the contact and the relative motion of piston and cylinder liner in a real engine has been designed and constructed. With this apparatus, the friction and wear behavior of a cast aluminum alloy piston with a graphite coating under different loads was studied, and the effectiveness of the apparatus was confirmed. The total wear of the piston skirt was higher under a higher load, and the upper part of the skirt surface (around the height of the piston pin) was worn more severely. The wear mechanisms were studied and, based on the test results and surface analyses, three main wear modes were believed to occur in the wear process of the piston skirt: abrasive, adhesive, and fatigue wear. The effects of skirt profile design, coating, and surface texturing on the friction and wear behavior of the piston skirt can be investigated well using the proposed apparatus, which can truly reflect actual working conditions and is useful to improve the tribological performances of piston skirts.

Automated summary

A piston skirt friction and wear apparatus that simulates the contact and relative motion of piston and cylinder liner in a real engine has been developed. This apparatus was used to study the friction and wear behavior of a cast aluminum alloy piston with a graphite coating under different loads. The results showed that the total wear of the piston skirt increased with higher load and the upper part of the skirt surface experienced more severe wear. Three main wear modes, including abrasive, adhesive, and fatigue wear, were identified. The proposed apparatus provides a useful tool to investigate the effects of skirt profile design, coating, and surface texturing on the friction and wear behavior of piston skirts.