Study On Process Of Metal Casting Automobile Steering Pump Al Alloy

As the quick development of the automobile industry, Al alloy becomes graduallyone of the important materials to reduce the weight of automobile. The AlSi10Mg(Cu)alloy was used widely in automobile industry, because their excellent performance influidity, air tightness, mechanical property, corrosion resisting without heat crack.However, the AlSi10Mg(Cu) alloy has a large crystal temperature range, easing toform mushy solidification. The common refinement modifier can not well improvethe mechanical properties of this alloy. Due to the high viscosity of liquid alloy, theinclusion is difficult to emerge from liquid alloy, and the refine treatment for Al liquidbecomes more difficult with a bad refine degassing. As well as the metal casting slagporosity, shrinkage and other casting defects, which cause a high scrapped rate.In this paper, the casting defects and microstructure of228automobile steeringpump were studied and the filling mold and solidification was simulated. By theoptimizing design of gating system, the filing behavior was improved, and reducedthe gas and inclusion in castings, simultaneously, the shrinkage porosity appearsmostly in the gating system. By the studying on molten aluminum refine,degeneration and clean process, the treatment method for liquid metal to reducecasting defects, refine grain, eliminate crack and remove the hydrogen and a smallamount of inclusion from the aluminum melt was suggested. The metamorphosis ofAl-Ti-C-Al-Sr has better fine grain than Al-Ti-B in this way and the intensity andplasticity of casting parts improved greatly as well. The tensile strength improved by10%, and elongation improved by40~50%. The optimal parameter of rotating bubblefloating method for the refine of AlSi10Mg microstructure was determined. Therotating bubble floating method is much better to deslag, degas than solvent method.The slag scrapped rate can be controlled below1.2%. The best solution and processparameters uses in batch experiments, makings the components pass rate increasedform75%to97%, and the mechanical properties of casting increased by20%...