ANALYSIS ON THE TEMPERATURE FIELD IN AN AXIAL SYMMETRIC METAL DIE WHEN USING ELECTROMAGNETIC HEATING FOR CRACK ARRESTING

A metal die with a half-embedded round crack is selected as object.The crack arresting is accomplished using electromagnetic heating by a pulse current discharge through the inside and outside of the die.The complex function method is used to solve for the temperature field around the crack tips in the metal die with half-embedded round crack at the moment when the current pulse is switched on.The temperature around the crack tip rises instantly above the melting point of the metal as a result of the heat concentration effect when the current pulse discharge and the metal melts instantly near the crack tip.Small welded joints can be formed in a small spherical region around the round crack tips inside the metal die.The curvature at the end of the half-embedded round crack increases instantly,so the formation of the main crack is arrested.