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Non-immersed cavitation jets represent an advanced surface treatment technology, characterized by their ability to generate cavitation in an air environment. Owing to their simple structure, these jets have found widespread application. In this study, both numerical and experimental investigations of non-immersed cavitation jets, incorporating fluid–solid coupling, are conducted. The microforming effects on T2 copper foils, induced by non-immersed cavitation jets, are analyzed by comparing simulation results with the experimental data, thereby validating the efficacy of this technique in foil microforming. Additionally, the flow field characteristics of the non-immersed cavitation jet are examined, focusing on the transient distributions of velocity, vortex structures, cavitation bubbles, and pressure at various dimensionless impact distances. The findings confirm that non-immersed cavitation jets are effective for microforming T2 copper foils, with an optimal dimensionless impact distance of 40 under the specified process parameters. The study also reveals that the non-immersed cavitation jet flow is inherently unstable, with the impact distance significantly influencing the evolution of vortex structures and cavitation bubbles. This research offers critical insights into the physical mechanisms underlying non-immersed cavitation jet microforming and provides both a theoretical foundation and experimental guidance for optimizing jet parameters to enhance microforming precision in future applications. [ABSTRACT FROM AUTHOR]

This study presents a new technology of flexible micro blanking with cavitation jet to improve the quality of micro blanking parts. The cavitation jet was simulated to analyze its meteorological volume fraction and the high-pressure phenomenon caused by cavitation collapse, which is crucial for the processing. The form ability of T2 copper foils under cavitation jet blanking processing was investigated for different shapes. The incident pressure and targeted distance of cavitation jet on the micro blanking form ability is studied, and the experimental results are correlated with the simulation. Furthermore, a linear relationship was observed between the critical blanking thickness and blanking size of T2 copper foil. Based on the characterization of the experimental results, it is found that the internal stress of the regular polygon-shaped blanking parts is unevenly distributed along the blanking contour during processing, resulting in the material to tear and produce defects like flaws and incomplete forming. In contrast, the internal stresses of the circular blanking parts are evenly distributed along the blanking contour, indicating high-quality blanking. Unlike traditional plastic micro blanking, the cut edges of the blanking parts using cavitation jet technology exhibited bending and pulling without prominent shearing marks. Under moderate incident pressure, the cut edge of the blanking part has few pulling marks and small burrs, ensuring uniform and high-quality blanking. [ABSTRACT FROM AUTHOR]

The demand for micro-components continues to increase, and there is a constant trend towards miniaturization and complexity. The traditional forming process micromachining technology has disadvantages such as high cost, complex manufacturing process, and long cycle, which cannot meet the needs of the industrial development. A new micro-forming process of metal foil arrays based on submerged cavitation water jets is proposed in this paper, and the shapes of the mold grooves are selected as triangular, quadrilateral, pentagonal, and hexagonal. The micro-jet and shock wave generated by the collapse of the cavitation in the submerged cavitation jet is used as the force-loading method of the foil to complete the flexible array micro-forming of the metal foil in this process. The results show that: the flow field at different incident pressures has low pressure and low pressure action time, fully satisfying the conditions required for cavitation to occur; the flooded cavitation water jet is concentrated in the downstream collapse area as a ring-shaped area; the more the number of single hole sides of the mold, the lower the deformation resistance in each area of the T2 Cu foil, and the clearer the T2 Cu foil forming profile. The submerged cavitation water jet array micro-forming studied in this paper is a low-cost, green, high-efficiency, and highly applicable forming process, which is a beneficial exploration and attempt at a new type of foil array micro-forming, which has high research value and good application prospects. [ABSTRACT FROM AUTHOR]