Study On Hydrogen Removal Of Aluminium Alloy

Aluminum and its metal alloy is easy to express out the characteristic inhale by chemical absorption in the melt process. And the gas must be dissociated and absorbed for the atom by the aluminum melt first. To monoatomic gas Ar,double atomic gas N2, O2, compound gas H2O(steam), CO, CO2, CmHn(Carbon hydrogen compound ) etc., because of their one's own inertia or of their complicated molecular structure or of their big molecular volume, it is difficult to dissociate into an atom state and be absorbed by the aluminum melt. Only the hydrogen is easy to be absorbed under dissolving the aluminum condition if it apt to dissociate to the atomic hydrogen. That is to say, the hydrogen is the only gas that is dissolved in the aluminum melting body in a large amount. And the solubility that the hydrogen in the solid state aluminum is very much little (0.034ml/100gAl), but in the melting state is very large (0.65ml/100gAl), that is means, it will cause the gas cavity because that the hydrogen appeared can't totally be discharged when the aluminum is crystallizing, which become the main impurity of the pollution in the aluminum alloy. It will influence product quality directly, will reduce some material's properties notably, such as the intensity, resistance to fatigue, bearing corrosivity, stress corrosion cracking, plasticity and so on, even cause the scrapping of the products. Along with the development of science and technology and industrialization, especially the developments of guided missile, spaceflight and electronic industrial technologies, it have put forward the requests to the material, such as light quality, high-strength, high-toughness etc. A lot of countries in the world are all carrying on the development and studying of the new-type high-strength, high-toughness aluminum alloy. Though the nonferrousmetals and its alloy are various in style, on industry is the commonly most used is still aluminum and aluminum alloy, copper and copper alloy at present. Among them, aluminum and its alloy is more apt to inhale and oxidize, so the issue that purification of the aluminum alloy is typical and urgency.In this paper, based on the theoretical analysis of dynamics of the hydrogen removal in the aluminum alloy on the swimming law of bubble, and on amount of the document of teferences , three basic ways have been summarized which could improve the kinetics terms:1. Increase the buble size as possible, in order to increasing A/V ratio;2. Reduce the diameter of the bubble as possible, and under the prerequisite of splashing not causing the aluminum melt, try to increase the speed of movement in the aluminum melt of the bubble, in order to strengthen the upgradation between the gas and melt, to increase the intensity of stiring, to improve the spreading quality ability (increase coefficient of conductivity K);3. lengthin the uourney that the bubble swims in the aluminum melt as possible, that is, to increase the time that bubbles dealt with the aluminum melt, thus improve the efficiency of hydrogen removal.Set about from these respects, further improvement of rotating and puffing argon method is be done. A kind of intermittent putting noble gas is be adopted. In this way, we can reduce the bubble size, increase the bubble density of distributing and delayed the time appearing in swirl. According to the similar theory of motive force, we also carried on the simulation of water conservancy to the hydrogen removal in the aluminum melt.