Research On Process Simulation Of Glass Particles Mixied And Dispersed In Semi-solid Slurry Of Aluminum Alloy

In daily life and production, it is resulted in a large number of scrap aluminum and waste glass with glass and aluminum consumption surging. Traditional recycling methods are mainly remelting. The use value is not high. Using semi-solid mechanical stirring method in preparation of waste glass/aluminum matrix composites is high added value utilization of the two kinds of materials effectively. In our early experiment, we find that mixing process parameters have a great influence on the material performance under the determined stirrer structure. In the paper, we studied the mixing process parameters’effect on glass particles dispersion in semi-solid slurry using simulation and experiment. We also explored the mechanism of glass particles dispersion、collision and agglomeration in semi-solid slurry. The optimized mixing process parameters are advanced. The main thesis research contents and conclusions are as follows:1.In this paper, the author reviewed the domestic and foreign scrap, waste glass recycling conditions, particle-reinforced composite materials, especially glass/aluminum composites research recently, as well as fluid mechanics software used in two-phase system research progress;2. Waste glass/aluminum matrix composites were prepared in early experiment. During the process of experiment, we find whether glass particles dispersed in semi-solid of aluminum alloy or particle agglomeration influenced by the selection of mixing process parameters;3.The rheological behavior of the semi-solid slurry based on scrap aluminum materials has been measured through a couette-type viscometer. The semi-solid slurry of aluminum-silicon alloy’s equation of rheological properties was founded;4. With the CFD flow simulation software FLUENT, the semi-solid slurry of aluminum-silicon alloy liquid’s flow field in stirrer has been studied. Simulation studies show that the distribution of flow field and mixing mechanism of glass particles can be used to guide and adjust the mixing process parameters,for example, stirrer speed, semi-solid slurry temperature,glass particles granularity, glass particles adding speed,stirrer times etc;5. The glass/aluminum matrix composites are made under the optimized mixing process parameters. The metallograph of cross-section of glass/aluminum matrix composites show that glass particles dispersion equably in composites. The simulation is effective in selecting the mixing process parameters;6.The semi-solid stirring mechanism is infiltration and friction swallow trap. Adding glass particles in the mixing semi-solid slurry, Aggregation of the particles can follow and scattered, and dispersed glass particles can move with the slurry in the stirrer at the same time. Dispersed glass particles scrub with the slurry particles, and the friction wet the surface gradually. Due to the distribution of a large number of solid-phase particles suspended in semi-solid slurry, glass particles are infiltration, and the solid particles are captured, surrounded. It is like the glass particles are trapped swallow by solid particles, which to avoid agglomeration of the particles. We explored the cause of particle agglomeration:When the surface of the glass particles appears melting liquid phase, the surface energy of glass particles melted and the solid surface can have difference. Its function is to make the glass surface area tends to shrink. During glass particles melting, collision and bonding process, molten particle is captured by more other molten glass particles close to it, which form into large particles of loose bonding. The buoyancy on the loosely bonded particles is far greater than the downward force of stirrer, so less than140particles added into stirrer can float in the liquid level, which can not enter the semi-solid slurry of aluminum-silicon. While the semi-solid slurry has maximum solubility as solvent, when the number of crystalline particles unsufficient to wrap up excess glass particles, resulting in increasing opportunities for glass particle collision, so the excess glass particles can easily reunion and float on liquid surface. The measure of avoiding paticle agglomeration are advanced according as agglomeration causes forementioned.