Optimization Of Forming Process And Defects Analysis Of Aluminum Alloy Die Casting

Pressure casting is an advanced, non-cutting special casting method .Die casting has a wide application prospect in automotive, motorcycle, internal combustion engine, electrics, instrument and aerospace due to their high dimension accuracy, excellent mechanical properties and high production efficiency and so on.Becasue liquid metal inflows into pressure room from casting cavity with rapid speed under high temperature .high pressure conditions,when pressure casting. During this process,air can easily enter into liquid metal and lead to air defect and Affect the quality of castings.In this paper, the pump lid of fuel pump casting for ZL108 aluminum alloy produced by HRHPower Limited Company has been investigated as an example. The basic theory, numerical simulation and experimental application have been studied for the problem that how to decrease porosity defects in casting and the main work and conclusions are as follows:Amplified the mechanism of forming porosity defects, analysesd the porosity defects and position distribution of pump lid in fuel pump ,and obtained that the gas content, filling velocity of metal liquid and filling mould states of piston in die chamber are main factors of influencing porosity defects, which provides a theoretical basis for following pouring, numerical simulation in filling system.In numerical simulation research ,simulated die casting runner and gating process at first. Under the diffent size of pressure room and diffent full degree of liquid metal,We can get the optimization shotting velocity of Pistons punch By simulated it's state campaign. Get the relations of Volume gas situation and Pistons punch velocity. Just the slow shot speed is 1.75m/s, Turbocharged time is 0.01s,the second injection speed is 3m/s, the Proportionof fulling pressure room is 0.25-0.75 effectively avoided gas enter into liquid metal and discharged gas of the pressure room. After that, simulated the Die Casting filling process of liquid metal .First use the spical soft Pro/E to construct the model of Die Casting part; Input it to another soft I-deas to form mesh and put the mesh document to the special soft ProCAST. In this way,We can simulate temperature field and velocity field at the same time and get the optimized processing parameter.The orthogonal experiment result of temperature field and velocity field concentration shows the optimized processing parameter is pouring temperature 700 ℃,injection speed 3m/s,mold initial temperature 210℃.Under the condition of orthogonal experiment process parameters,we actually produced Die Casting pump cover. The practical die casting process has showed that defects and dimensions of die casting part meet the demand of usage.