A model for deformation in high energy rate micro forming process

This paper presents an investigation on high energy rate micro forming (HERMF) of a thin aluminum foil using a high velocity forming (HVF) technique. A model is proposed for the work of deformation and efficiencies involved in every stage of energy transfer. The forming action has been achieved through incident shockwaves, which cause plastic deformation in the blank to take the shape of the die cavity. The shockwaves are generated by a rapid capacitive discharge of energy across a fuse wire inside the water. The paper presents an analysis to predict the amount of energy required for a desired depth of hemispherical deformation, based on the principles of plastic deformation and volume constancy. The energy transferred from the capacitor bank to the fuse wire is modeled using Kirchhoff’s voltage law and the Joule heating principle. An indigenous micro-electro-hydro-forming (EHF) setup developed in-house is used to validate the analytical model developed through a set of experiments. Readings are optimized against the number of parameters present in the entire process. Validation for the suggested analytical model is carried out by comparing theoretical and experimentally measured values of the depth of deformation of a 20-μm thick aluminum foil. The results obtained are encouraging, and the highest error in the predictive ability of our model was found to be 30 %. To the best of our knowledge, this is the first attempt at analytically modeling the depth of deformation for a given value of supplied electrical energy in the micro-domain.