Research And Simulation On Lost Foam Casting Process Of The Ductile Iron Lift Arms

Casting simulation technology has been widely used in the actual production. Itplays a huge role in the development and trial manufacture of new product, in theprocess optimization of old products and in the low-cost quality control, etc., butthere’s few successful case on applying lost foam casting simulation technology tocomplex three-dimensional castings. In order to promote the development of applyingthe advanced computer simulation technology to lost foam casting industry in China,we use three-dimensional modeling software UG, use3D casting simulation softwareProCAST and Visual Environment software to study and simulate the lost foamcasting process of the ductile iron lift arms.In order to ensure the utility value of the simulation results, the simulation mustbe set reasonable parameters, therefore, this paper firstly discusses the specialparameters in the simulation of lost foam casting process and in the simulation ofshrinkage poriosity in ductile iron castings, different simulation results based onapplicative examples show different parameters affect the accuracy and utilitybetween the simulation and the real production, the filling&solidification simulationmethods of ductile iron lost foam casting with ProCAST and its implementation areshown.Then, in order to analyse the complex thermophysical situation during the lostfoam filling and solidification of the lift arms accurately, ProCAST is applied tosimlulate the casting process of two trial schemes: the bottom gating system schemeand the top gating system, and through the comparison of simulation results with thetrial results, the precise thermophysical model to simulate the ductile iron lift armslost foam casting process is established.Finally, in order to obtain qualified castings, a improved casting scheme, stepgating system scheme is developed, according to the structural characteristics of thelift arms and the advantages and disadvantages of two trial schemes. Then useProCAST simulated the improved scheme based on the precise thermophysical modelobtained above, the results show that the new scheme could solve the concertratedshringkge holes in trial manufacture products, though there’s still a few concentratedshrinkage porosity occured. After the pouring validation, we know the simulation isconsistent with the actual. To minimize the shrinkage poriosity, an optizimation way is proposed, based on the above discussution of how different sands affect the shinkageporiosity in iron casting products. In the optimal scheme chromite sand cores is preburied in the fossa of two arms and the step hole, the final casting test results provethat this optimal scheme can reduce the shrinkage defects most.This paper does a useful study on applying computer casting simlation to lostfoam process’ optimization and quality control, the research shows that based onreasonable parameters and accurate thermalphysical model, applying lost foamcasting simulation technology can grasp the whole casting process and predict thecasting defects accurately, the simulation results could guide the engineers to designand optimize casting schemes. It indicates that the application of the "computer trialand error" in the actual production can avoid the "artificial trial and error" times asmuch as possible, can reduce the human resources loss and financial loss, can savehigh production costs. The conclusions of this study can effectively guide the lostfoam casting simulation in practice production and the actual production of lost foamductile iron castings.