RESIDUAL STRESS MODELING AND ANALYSIS IN AISI A2 STEEL PROCESSED BY AN ELECTRICAL DISCHARGE MACHINE
Abstract
Due to the creation of a significant temperature gradient, electrical discharge machining (EDM) causes localized, high thermal stress in a tiny heat-affected zone. This thermally developed stress leads to fatigue life and strength decrement, micro-cracks and probably catastrophic failure. On AISI A2 steel, a mathematical model based on finite-element analysis was constructed to estimate the temperature field and associated thermal stresses. In this present research work, the heat-flux distribution in a single spark during EDM is considered to be Gaussian distributed. The model first calculates the temperature distribution, and then uses this temperature field to determine the thermal stresses. It was observed that the stresses surpass the workpiece material’s yield strength near the center of the spark and this gradually weakens as the distance from the center increases.
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