Study Of Numerical Simulation On Casting Process Of Aluminium-Alloy Cylinder Of Automobile

Casting properties and process improvement of A356 aluminium alloy that is used to replace traditional cast iron to product automobile engine are investigated in the present paper. So the strength of Al-alloy cylinder can be enhanced and its defect can be reducede ultimately.Firstly, the effection of alloying composition on founding properties and strength of Al-alloy was analyzed and the suitable alloying composition in Al-alloy material were choosed. And then the method of numerical simulation is used to study the casting process of A356. The effects of flow field and temperature field on the microstructure and defects distribution of cylinder casting is analyzed by ProCAST software and experiments that the cylinder is made under the condition of the optimize parameters from ProCAST. At last, the joint performenc between Al-cyliner and cast iron cylinder sleeve is investigated.The results show that the liquidity of liquid metal can be greatly enhanced by suitable Si element and the line shrinkage ratio of A356 is reduced. And ageing strengthening can be made by the phase Mg2Si formed in alloys. The resistance of Stress corrosion is improved and the transition temperature from GP zone to middle phase was reduced because of the existence of the proper quantities Cu. A small amount of Fe can riase the recystallization temperature of Alloy. but its mechanical properties was reduced, because the a-Al grain was throughed by the needle-likeβ-iron formed the over-dose Fe.Based on the knowledge of the origin of numerical simulation, development and application in the foundry industry, Theory of numerical simulation and the operational principle by ProCAST on the gravity sand casting process was probed depthly. Finally, through analyzed the influence and its weighting factor of technological parameters on the performance of Al-alloy cylinder, the optimize technological parameters obtained by calulating is pouring temperature 725℃, preheating temperature of cylinder sleeve 450℃, pouring times 21s, bottom gating system and rotated solidification. Then, the cylinder is made under the condition of above parameters and the microstructure of the cylinder was observed. The results show that the microstructure and defects distribution which is simulated by ProCAST software are good agree with the experiments.