Numerical Simulation And Process Optimization Of Low Pressure Die Casting Of Aluminum Alloy Wheel Hub

This paper took a modlel of A356 low pressure casting aluminum alloy wheel as the research object,by the numerical simulation of temperature field and flow field in the casting process, got the important parameter of metal flow and temperature distribution in the casting.At the same time, it predicted the defect of this casting found the causes of the defects. By analyzing the causes of the defects designed reasonable optimization scheme.To apply the orthogonal design to confirm the optimal combination parameter of gating system is one good method for effectively improving the quality of the products.Created the 3D-model of wheel hub casting and mould by Pro/E which is 3D CAD softwareand assembled them in Pro/E enviroment.Then,Using ProCAST,a casting simulation software,simulated the original casting processes. By analyzing the result of simulation,found initial solution filling speed is larger, existing the gas volume and injection phenomenon.The solidification temperature field distribution is not uniform,in the joint of spokes and rim appear hot section.Due to premature closure of feeding channel,caused of the defect of shrinkage cavity and porosity.Obviously,need to optimize the process parameters.Using orthogonal experiment method,setted the pouring temperature, casting speed and the holding pressure of 3 factors and 3 levels orthogonal experiment.Combining with the numerical simulation of temperature field and flow field.a comprehensive analysis of the technology after the optimization parameter group was obtained:pouring temperature700℃, casting speed of 6.7KPa/s, pressure 70 KPa.To solution the defects of aluminum alloy wheel hub pinhole, by analyzing its mechanism, using the comprehensive experiment design method of three factors and two levels experiment, through the observation and determination of the density profile determined the optimal combination of process parameters are:nozzle speed 400r/min, in addition to air temperature is 720℃, processing time 150S.The process parameters were optimized, can effectively reduce the volume of gas, misrun, shrinkage and pinhole defects, greatly shorten the low-pressure casting production cycle, improved product quality.