Cavitation Flexible Microforming Mechanism and Quality Analysis of Complex Micro-Box Components

With the widespread application of micro-electro-mechanical systems (MEMS) in advanced manufacturing fields, the demand for micro-components is increasingly shifting towards miniaturization and complexity. Traditional micro-forming processes are insufficient to meet the industrial production needs. To enhance the forming performance of components with complex micro-features, a novel cavitation-jet-based flexible micro-forming process is proposed. The dynamic evolution and collapse characteristics of cavitation clouds were observed through numerical simulations, and the distribution pattern of equivalent stress during the workpiece forming process was analyzed. Based on the characteristic dimensions of the microphone shell, a mold was designed, and forming experiments on T2 copper foil were conducted using a cavitation jet experimental setup. The study focused on the effects of incident pressure on the forming performance and quality indicators of the formed samples, such as forming depth, surface roughness, thickness thinning ratio, and nano-hardness. The research results indicate that as the incident pressure increases, the forming depth of the micro-shell gradually increases, with the maximum depth approaching the design dimensions of the mold cavity. Additionally, a linear positive correlation was observed between the surface roughness and thickness thinning ratio of the formed samples and the incident pressure. Under the processing parameters of an incident pressure of 23 MPa, the formed samples exhibited nearly perfect conformity with the mold cavity, along with good surface quality and forming uniformity. The overall hardness of the shell was improved. The cavitation jet micro-forming process studied in this paper is a low-cost, environmentally friendly, and highly adaptable forming method, which can be applied to the processing of complex micro-box components, showing promising application prospects.