Feasibility study on the micro-forming of novel metal foil arrays based on submerged cavitating water-jet impingement

Abstract

To solve the problems of high cost and complex technology in the current plastic forming method of metal foil, a micro-forming method of submerged cavitation water-jet metal foil array with cavitation collapse shock wave loading is presented in this paper, which has advantages of high efficiency, flexibility, low cost and environmental protection. 304 stainless steel foil array micro-pore formation was taken as an example in this paper. The mixing nozzle was designed and three regions where the cavitation water-jet acts on were analysed. The influence law of target distance, impact time on the forming depth and uniformity of metal foil array was examined and the optimal position of array micro-forming in the impact zone of vacuoles collapse was revealed. Results indicate that the depth and uniformity of array micro-pores in the impact zone of cavitation collapse increases with time. However, with the increase of the target distance, it will increase first and then decrease; the depth of the array micro-pores on the radius r=13.6 mm can reach 166.4 μm, and the variance is only 5.9 μm under the condition of impact time of 5 min, target distance of 120 mm and pressure of 20 MPa; the maximum surface roughness is 1.54 μm and the thinning rate is between 2% and 10%.