​Numerical Simulation of Melt Mold Casting for Aluminum Alloy Parts

        With the development of electromechanical product parts to the direction of thin-walled, complex, lightweight, aluminum alloy precision casting technology has received great attention. Melt mold precision casting castings produced by the dimensional accuracy, surface quality than other casting methods to be high, there is a wide range of prospects for application. However, there is a wide range of process parameters and mutual influence, the generation of a long cycle, casting thin-walled, complex curved surfaces of the scrap rate is higher and higher shortcomings.

      For the casting process parameters set orthogonal test program, the use of ProCAST software on the melt mold precision casting casting process flow field, temperature field, stress field numerical simulation, to determine the factors of the optimization of the combination of various levels of the program. Fused silica, which minimizes both density and linear expansion, is selected to formulate the coating: fast-drying silica sol, which has good casting quality, high generation efficiency and green environmental protection, is selected as the shell-making binder. Based on the three-dimensional lattice model theory and Monet's theory in rheology, the radius ratio and content ratio of the refractory particles were calculated by using the sphere dense stacking model and the geometric relationship of the sphere center. The fine powder content and powder-liquid ratio of the coatings were derived using the one-factor rotation test method. The fast drying silica sol coating formulation was derived from the results of the coating viscosity test. Through the convection drying orthogonal test of flat plate specimens, the drying time and deformation of the specimens are coordinated, and the optimized combination scheme of process parameters is derived from the extreme difference analysis.

       Finally, the shell making and casting tests of motor frame and floor flange parts were carried out. The whole shell making process took about 34 hours, and the production efficiency was greatly improved. After dewaxing, the surface of the shell is smooth, without cracking phenomenon, and the quality is good. The results of the alloy casting test show that the optimization of process parameters is highly reliable and of great economic significance.