Development Of Magnesium Alloy Automotive Steering Column Bracket

Lightweight is one of the main trends in vehicle development, it has importantsignificance for saving energy and protecting the environment. Magnesium alloy is widelyused in the automobile lightweight research for its low density, high strength and goodshock absorption performance advantages. Automotive steering column bracket is animportant component parts in steering assembly system, it is usually made of aluminumalloy. In order to study the feasibility of using magnesium instead of aluminum tomanufacture automotive steering column bracket, the stress analysis of the parts made oftwo different materials was studied in finite element method; the casting processparameters was designed for magnesium alloy steering column bracket, and sprue, runner,ingate size of gating system was calculated; the magnesium alloy steering column bracketwas a successful trial through the synthesis of resin sand and modeling process; studyingheat treatment on microstructure and mechanical properties of magnesium alloys bymicrostructure observation and mechanical test.The results show that the replacement of material has less affection on stressmagnitude and distribution in the part. Structure optimization and stiffeners were designedto improve the force conditions of parts and reduce stress concentration, and most of theequivalent stress values below40MPa, the structural strength of the part has beensignificantly improved. Using Flow-3D simulation software for filling simulation and9different process parameters optimization, the optimal casting temperature is700℃, sandbaking temperature is200℃, in the suitable resin sand molding process, the furan resinsand accounted for1.2%by sand weight, the hardener accounted for45%by resin weight.The magnesium alloy steering column bracket was a successful trial through the synthesisof resin sand and modeling process, the melting of magnesium alloy and pouring processes.It has a clear outline and good quality. Cracks, slag, porosity and other casting defects werenot found in the casting by X-ray flaw detection. The casting showed that tensile strength153MPa, hardness65HB, elongation rate4.4%. By heat treatment (410℃×10h+225℃×10h), the microstructure and mechanical performance of the casting have been significantly improved, casting tensile strength reached191.59MPa, hardness69HB, elongation rate3.8%. Its tensile strength increased by25%. Magnesium alloy steering column bracketweighs1.36kg, the weight compared aluminum alloy bracket (1.97kg) decreased by31%,this research achieved the lightweight of automotive part.