The Effect of Electroless Sea Sand-Coated Particle on the Mechanical and Physical Properties of Al6061/Sea Sand Composite

The use of sea sand as a reinforcing material in aluminum matrix composites (AMC) offers a promising solution for producing economical and lightweight materials. A significant challenge in this material is the low wettability of the sea sand’s surface with respect to metal particles. The objectives of this research are to enhance the wettability of sea sand to enable its practical use as a reinforcement material in AMCs. The study was conducted experimentally in two stages. The first stage involved an electroless coating process. This was carried out by mixing 40 ml of nitric acid (HNO3) with 0.5 g of aluminum (Al) powder and varying amounts of magnesium (Mg), specifically 0.1 g, 0.2 g, and 0.3 g . The coated sea sands were analyzed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). In the second stage, an aluminum 6061/sea sand composite was produced by stir casting, with the coated sea sand from the first stage as the reinforcement. The composites were then tested for density, porosity, and hardness. The results of the first-stage analysis indicate that Mg successfully modifies the surface of sea sand particles, as confirmed by SEM, EDS, and XRD tests. These tests reveal that the surface structure of sea sand becomes rough due to the presence of metal oxides. In the second-stage analysis, it was found that the Al6061/sea sand composite containing 0.1 g of Mg performed best among the variations. This variation achieves the highest values of density, porosity, and hardness at 2.643 g/cm^3, 1.84%, and 61.5 BHN , respectively.