Research Of Melting Purification Process Of ZM6Casting Magnesium Alloy

With low density, relatively high intensity and stiffness, easier cutting processingcapability and good shielding properties, magnesium alloy is recently used in most ofindustries, such as, automobile, electronics, navigation, etc. Unfortunately, the nonmetallicinclusions in the alloy impair the mechanical and corrosion properties of the alloy and thenlimit the usage of this alloy. Therefore, it is meaningful to improve melting process ofmagnesium alloy and to increase purity of magnesium alloy melt.This article select the ZM6casting magnesium alloy as experimental material, detailedand comprehensive study of the various factors that affect purity of magnesium alloy meltingliquid. Including refining agent, refining methods, refining temperature, standing time. Andthe influence on the purity of magnesium alloy liquid by different ways of protection.The composition of the inclusion adopt the EDS to analyze, can be concluded that theinclusion in molten magnesium alloys can be divided into two categories. One kind ofinclusion is oxide inclusion given priority to with MgO, another kind of inclusion is fluxinclusion given priority to with chloride, its main composition is NaCl, MgCl2, KCl and asmall amount of CaCl2. Look from the appearance, needle and bar most of MgO inclusion,rotundity most of chloride flux inclusions. The results indicated that the best purifying effectwhen refining agent at1%and refining temperature in730℃to750℃, continuous refiningpurification effect is better than the discontinuous refining. In flux protection, best purifyingeffect when smelting temperature720℃, the standing time of0.5h, in gas protection, bestpurifying effect when smelting temperature740℃, the standing time of1.5h. The use of gasprotection is easier to obtain pure liquid metal than flux protection.