Effect of coatings on thermal conductivity and tribological properties of aluminum foam/polyoxymethylene interpenetrating composites

The purpose of this work is to solve the problem of interface bonding in aluminum foam (AF)/polyoxymethylene (POM) interpenetrating phase composites (AF/POM). Silane coupling agent (KH-550), graphene oxide (GO), sulfonated graphene (S-GNS) and graphene (GS) coatings were prepared on the surface of AF, respectively, as an interfacial transition layer. The molten modified POM(POMC) was injected into the hole of coated AF by injection molding to prepare different kinds of coated AF/POMC. Thermal conductivity, friction coefficient and wear loss of coated AF/POMC were analyzed, and the wear mechanisms were discussed in detail based on evidences from SEM. The effect of coatings on thermal conductivity of coated AF/POMC was also verified by ANSYS. The investigation has shown that four kinds of coating are successfully covered on the surface of AF, respectively, and the morphology of S-GNS coating is the smoothest. The thermal conductivity of coated AF/POMC is higher than that of AF/POMC. The thermal conductivity of S-GNS-AF/POMC reaches the highest value of 2.25 W m−1 K−1, because S-GNS coating plays a role in reducing the thermal resistance of the interface between AF and POMC phases. The friction coefficient and wear loss of coated AF/POMC are also lower than that of AF/POMC. Three types of graphene coating(S-GNS,GO,GS) as an interface transition layer between AF and POMC phases can homogenize friction, accelerate heat transfer and reduce the friction coefficient and wear loss of composites. Through ANSYS thermal steady-state simulation, S-GNS-AF/POMC has the maximum number of heat flow paths and the highest heat flux compared with other materials.