The Effect of the Mixing Model on the Characteristics of Cu-Ni-Mo-4SiC Composite Synthesized by Powder Metallurgy

Abstract

The mixing method plays a decisive role in achieving microstructural uniformity and in defining the mechanical, tribological, and electrical performance of composite materials. This study aims to evaluate the characteristics of a Cu-Ni-Mo-4SiC composite produced using various powder mixing models. The composites were prepared through powder metallurgy employing horizontal mixing (HM), V-mixer blending (VM), and mechanical alloying (MA). The powders were mixed further, compacted at room temperature, and subsequently sintered at elevated temperatures. The resulting composites were examined using various characterization methods, including Scanning Electron Microscope (SEM) – Energy Dispersive Spectroscopy (EDS) for microstructural observation, X-ray Diffraction (XRD) for crystal structure identification, measurements of density, Vickers microhardness, wear resistance, and electrical conductivity at room temperature. The results show that mechanical alloying led to a finer crystallite size, a more homogeneous Cu-Ni matrix, better distribution of Mo and SiC particles, and reduced porosity. Hence, the highest performance was attained in the MA composite, which has a hardness of 65.1 HV, specific wear rate of 5.56 × 10-5 mm3/Nm, electrical conductivity of 62% IACS, and resistivity of 2.78 × 10⁻⁸ Ωm. This can be explained by finer grains, reduced particle aggregation, and even dispersion strengthening. As a result, under electrical service at room temperature and dry sliding load of 10 N for 20 min, the MA composite could serve as a material for electrodes and sliding electrical parts.