高耐磨 GNPs/AlSi10Mg 复合材料制备及其耐磨机制研究

Through the surface modification of graphene nanoparticles (GNPs) by ethyl cellulose (EC), combined with solution ultrasonic dispersion and wet ball milling, GNPs and aluminum matrix were uniformly mixed and GNPs damage was suppressed. Then, highly wear-resistant GNPs/AlSi10Mg composites were prepared by the suppression of interfacial reaction through rapid sintering with discharge plasma. The microstructure and wear-resistant properties of GNPs/AlSi10Mg composites were characterized and analyzed by scanning electron microscope, transmission electron microscope and friction testing machine. The results show that moderate addition of GNPs can effectively improve the mechanical properties of the composites. When the addition amount of GNPs is 0.5wt%, the wear rate and coefficient of friction of the composites are the lowest, which are 7.8×10^-4 mm³/(N·m) and 0.417, respectively. The wear rate is reduced by 28.4% compared with that of the matrix material (10.9×10^-4 mm³·N^-1·m^-1). The wear mechanism of GNPs/AlSi10Mg composites is mainly abrasive wear, accompanied by slight oxidative wear and adhesive wear. During the friction process, when the composite specimen is in contact with the dyad, GNPs emerge on the surface to form a thin film under the action of shear force, which can be used as a lubricant to reduce the contact point between the dyad and the matrix, preventing excessive spalling and delamination and thereby protecting the matrix.