Research on Micro-nanoscale SiCp/6061Al Composite Coating Using High-Pressure Cold Spray

Cold spray deposition of SiCp/Al composite coatings shows great potential in the field of material protection. However, the strengthening effect of single-scale reinforcement on the composite coating’s performance is limited. To further enhance the mechanical properties of the composite coating, a dual-scale reinforcement model with both micron and nanoparticles was adopted. The addition of nanoparticles further enhances the individual scale advantages and coupling effects of SiC particles, resulting in a composite coating with excellent comprehensive properties, thus meeting the combined requirements for strength and wear resistance. Micro-nano-SiCp/6061Al composite coatings were designed and prepared using high-pressure cold spray technology. The preparation process, microstructure, and property changes of the micro-nano-reinforced composite coatings were systematically studied. The results indicate that cold spray can successfully produce micro-nano-dual-scale SiCp/6061Al composite coatings. The SiC/Al nano-composite coating exhibits a dense structure with micron and nano-SiC particles uniformly dispersed throughout the 6061Al matrix. Compared to single micron-reinforced SiCp/6061Al composite coatings, the addition of nano-SiC particles significantly strengthen the 6061Al matrix. The hardness of cold-sprayed micro-nano-reinforced SiC/6061Al composite coatings increased by 21.9% and the wear resistance has been improved substantially, while the wear rate reduced by 41.92%. With the content of nano-SiC particles increasing, the hardness and wear resistance of the micro-nano-reinforced SiC/6061Al composite coatings initially increase and then decrease. When the mass fraction of nanoparticles reaches 5%, the hardness peaks at 100.64 Hv, while the wear rate decreases to 1.0390 × 10⁻⁴mm³/N m. The proposed cold spray method for preparing dual-scale SiC/6061Al composite coatings could provide data support for future applications of SiC particle-reinforced aluminum matrix composite coatings.