Effect of fumed silica in rice bran wax-epoxy coating on aluminum substrate: mechanical, thermal, and water absorption properties

Surface technology is making emerging trends in engineering environment. Wax-epoxy coatings are one of the surface improvers, which are also found in nature and appear on plant leaves, such as lotus leaf and some insect wings. The present study was focused on this stream line where the effect of the fumed silica addition into the rice bran (RB) wax-epoxy coating on aluminum substrate. The main aim of the present study was to find how the addition of RB wax modified the base properties of epoxy resin and what could be the significant of adding fumed silica as strength booster. The coatings were done using spray coating technique at ambient temperature. According to the results, the addition of RB wax into the resin along with fumed silica improved the mechanical, hydrophobic nature, thermal stability, and wear resistance. A highest flexural strength of 102 MPa, lap shear strength of 21.65 MPa, microhardness of 88 shore-D, Sp. wear rate of 0.003mm3/Nm, and the lowest COF of 0.38 were noted for composites made using rice bran and fumed silica particle. The density remains same due to low density wax material addition with noticeable improvement in surface hardness. The SEM micrographs revealed flat fractograph for pure epoxy and high wavy structure for wax mixed fumed silica dispersed epoxy coating. The surface roughness of coated surfaces explicated less surface roughness than uncoated one. These eco-friendly coatings could be used in automobile, medial, and biological applications.