FORMING METHOD CAPABLE OF MINIMIZING GRAIN SIZE OF MAGNESIUM ALLOY BY IMPROVING MICROSTRUCTURE OF MAGNESIUM ALLOY THROUGH PLASTIC DEFORMATION OF MAGNESIUM ALLOY USING ECAP(EQUAL CHANNEL ANGULAR PROCESS)

摘要

PURPOSE: To provide a method for maximizing grain refinement of magnesium alloy when an ECAP(equal channel angular process) is applied to magnesium alloy to increasing ductility of magnesium, maintain a certain yield strength or more and expect to improve high temperature superplasticity according to grain refinement. CONSTITUTION: In a magnesium alloy manufacturing method for increasing ductility of magnesium alloy and suppressing strength drop generated due to ductility increase of magnesium alloy at the same time, the method for securing strength of magnesium alloy through grain refinement through ECAP(equal channel angular process) comprises a process comprising a step I of heating magnesium alloy and die for ECAP at a temperature of 280 deg.C or more, a step II of performing ECAP on the magnesium alloy, a step III of preheating magnesium alloy and die for ECAP at a temperature between 200 deg.C and 250 deg.C, and a step IV of performing ECAP on the magnesium alloy, wherein the step III and the step IV are repeated for two or more times after repeating the step I and the step II twice, wherein an angle between an axis line passing through the center of an entrance of the die and an axis line passing through the center of an exit of the die for the ECAP is between 85 degrees and 135 degrees.