Preparation Of Foamed Copper And Study On Tribological Behaviors Of Composites Reinforced By Foamed Copper

In this paper, we prepared foamed copper/epoxy (FCE) composites and foamed copper/phenolicresin (FCP) composites, studied the influence of lubricating fillers, the porosity of foamed copper andexperimental load and speed on friction performance, and explored wear mechanism of FCEcomposites and FCP composites. The main contents are as follows:1. We used polyurethane foam as the substrate to prepare foamed copper of different porosity,from10PPI to40PPI. The porosity of foamed copper material is more than90%, and the pore size isbetween0.63mm and2.54mm. The foamed copper material has good mechanical properties after theheat treatment.2. The friction coefficient of FCE composites gradually decreases as the amount of MoS2increases; however, the wear rate initially decreases and then increases. When the MoS2content is30percent, the wear rate reaches a minimum. The wear rate decreases as the porosity of foamed copperdecreases, but porosity has little effect on the friction coefficient. As the rotation speed of the grindingsteel plate and the applied load on samples increase, the wear becomes more significant.Depth-of-field microscopy and scanning electron microscopy were employed to observe theworn-surface morphologies and wear mechanism. At low load and speed adhesive wear is the primarymode of surface wear and at higher speeds FCE composites takes the form of fatigue wear.3. The friction coefficient of FCP composites gradually decreases with the content of graphiteincreases. When the content of graphite is15percent, the FCP composites show the best wearresistance. The higher the porosity of foamed copper is, the better tribological properties of FCPcomposites are. High speed and high load increases the heat generated in the process of friction andwear, which reduce the mechanical properties of the material and lead to the increase of the wear rate.Worn surface morphology showed that slight abrasive wear and adhesive wear is the main wearbehavior of FCP composites. At higher speeds FCP composites present a large surface spall, leadingto a sharp increase in the wear rate.