Research Of Double Electrode & Electro Slag Purification Technology Of Aluminum Alloy

The development of modern science and technology put higher request to Aluminumalloy. The aluminum of high purity and high thermal conductivity, good plasticity andtoughness has become the important materials of aviation industry, automobile industry. Thequality of aluminum alloy mainly depends on the casting quality, reducing the gas andinclusion is the key of the quality.The paper studied the ZL101, ZAlSi6Cu3Mg ZL205A by citing the principle ofelectro-slag casting (ESC) and the method of double electrodes & electric flux purification, atthe same time, researched the technological parameter and effect of purification. In the courseof the study, we came to the following conclusions:(1) The flux used in this experimental process does not react with liquid, and they won’tdissolve each other. The melting point of the three kinds of mixture below the temperature ofaluminum when be purified. The flux can form a continuous surface layer, because of goodfluidity, and cover the surface of Aluminum, which can stop the invasion of the hydrogen inthe air, and can adsorption, dissolved or broke Al2O3and so on, all of this meet with therequirement of aluminum alloy purification.(2) The paper analyzed the composition of Aluminum by Direct-Reading Spectrograph,and came to the conclusions as follow: the content of elements in Aluminum like Si、Fe is notchanged, but the content of Mg element changed a lot. At the same time, we found that, theMg element in ZL205 reduced about 48% for heating after purification.(3) After the electric flux purification treatment, the tensile strength of ZL101 reached 286.8MPa, exceeded that of before purification, the elongation also increased a litter; thetensile strength and elongation of ZAlSi6Cu3Mg were increased a lot after purification; afterpurification, the tensile strength of ZL205 is lower than before, and the elongation is lowertoo. When added the inter-alloy of Al—5Ti after purification and tested its physical property,we found that the tensile strength is equal to that of before, and elongation, but the elongationreached 11%, increased 100%.(4) The paper ensured that electricity had great effect on the content of Mg in ZL101alloy, the flux ratio comes second, and the thickness of slag is the last. But when it comes toZAlSi6Cu3Mg, the factor sequence has changed, first is the thickness, second is electricityand the flux ratio is the last. In order to stabilize the composition of Aluminum, the bestprocess parameter for ZL101 is current-275A, flux ratio-65﹪KCl +25﹪MgCl2+10﹪Na3AlF6 and flux thickness-80㎜, and that of ZAlSi6Cu3Mg is current-300A, flux ratio-60﹪KCl +30﹪MgCl2+10﹪Na3AlF6and flux thickness-80㎜.(5) In the process of additional experiment, after the purification which used thetechnological parameter of current-250A, thickness-60㎜, and add a good amount of Al-5Tialloy, we found the tensile strength of ZL205 is 486.06 MPa, which is equal to that of beforepurification. But the elongation reached 11%, be twice of before.