<p>High-volume-fraction SiC particle-reinforced aluminum (SiCp/Al) metal matrix composites (MMCs) are widely utilized in the electronic packaging of aerospace equipment because of their low density and high thermal conductivity. However, the extremely high hardness of SiC and compact structure of electronic packaging components pose significant challenges to conventional manufacturing techniques. Severe tool wear can reduce the processing efficiency and increase the manufacturing costs. Therefore, this work introduces a fast electrical discharge (ED) milling approach for machining high-volume-fraction SiCp/Al MMCs. This method was successfully applied to the fabrication of gas-film holes. Nevertheless, Ni-based superalloys differ significantly from SiCp/Al, and their material-removal mechanisms and machining capabilities represent core knowledge gaps. Consequently, this study employed an observation setup based on a high-speed camera to capture the gap discharge phenomenon and analyze the machined surfaces and generated debris. This analysis revealed the material-removal processes and mechanisms under two processing conditions with pulse durations of 50 μs and 500 μs. Additionally, the capability of fast ED milling to process high-volume-fraction SiCp/Al MMCs was initially verified through sample machining. The experimental results demonstrated that this method could create parts with complex and precise geometries, achieving satisfactory results in terms of machining accuracy and surface quality. Dimensional errors could be controlled within  ± 50 μm, and the average surface roughness was less than 3 μm.</p>