Numerical modeling of electrical discharge machining of Ti-6Al-4V

Ti-6Al-4V is one of the most widely used materials for successful applications in aerospace, automotive, and biomedical industries due to its high specific strength, excellent mechanical and thermal properties, and outstanding corrosion resistance. These properties make Ti-6Al-4V very difficult to be machined using conventional manufacturing processes. The electrical discharge machining (EDM) is a very viable solution to machine Ti-6Al-4V. However, the EDMed surface usually undergoes phase transformation during the EDM process due to the rapid heating and cooling in EDM. In this paper, the commercial FEM software package Abaqus is used to investigate the effects of EDM conditions on the crater size, phase transformation in HAZ, and the residual stress distribution in EDMing of Ti-6Al-4V. The phase transformations of Ti-6Al-4V alloy during EDM are modeled based on phase transformation kinetics and flow stress is described using the rule of mixtures. Experiments are conducted to validate FEM model, which are then used to predict crater size, phase transformation and residual stress for different discharge energy levels.