Process Design And Numerical Simulation Of Die-casting Ultra-thin Laptop Fan Cover

With the rapid development of mobile processing technology and the electronics industry,notebook computers have become widely used products.Thin and light,portability,and good heat dissipation have also become the development trend of notebook computers.Aluminum alloys are widely used in notebook computer parts because of their light weight and high specific strength.Die casting is a common forming process for aluminum alloy products.In actual production,thin-walled aluminum alloy die castings often suffer from difficulty in filling and shrinkage.With the rapid promotion of CAD/CAE technology in the design of die casting molds and optimization of molding process parameters,the quality and production efficiency of die castings are effectively improved.This paper mainly studies and optimizes the die casting process of notebook fan covers.The fan cover material is made of ADC12 aluminum alloy.This part is a sheet-like thin-walled part that is used to cover the cooling fan in the notebook.The thickness of the main wall is 0.5mm.The outer contour of the parts is provided with convex lugs and grooves for assembling,and there are left and right positioning rods with different shapes below.The whole casting have a thin-walled structure and it is not easy to form.If the feeding is insufficient,shrinkage porosity and shrinkage cavity may affect the quality of the castings,resulting in failure in normal assembly and use.Firstly,the die casting process and the tooling design of the notebook fan cover are determined.According to the structural characteristics and application requirements of the notebook fan cover,a process analysis of the fan cover is made and the parting surface was determined.And the three-dimensional design software UG was used to perform the gating system design,the overflow system design,the ejection mechanism design,and the design of mold frame and guide mechanism.At the end of the design,an overall assembly drawing of the mold is drawn and the design of the die casting mold was completed.Secondly,the ProCAST software was used to simulate the die casting process of the notebook fan cap.Three process parameters which have the greatest influence on the quality of castings are studied by selecting the pouring temperature,the injection velocity and the preheating temperature of the die.The influence of the parameters on the filling process,the solidification process,the shrinkage porosity and shrinkage cavity of the fan cover castings is analyzed.Thirdly,the orthogonal test scheme is designed to further optimize the die casting process parameters.Taking the casting quality index,filling state,and solidification state as the test indexes,the orthogonal table of L₉?3³?was set up with pouring temperature,injection velocity and preheating temperature of the die as test factors.The orthogonal test of three factors and three levels was carried out.The line graphs were drawn to visually analyze the effect of each parameter on the quality index of castings and the state of filling and solidification.The simulation results were analyzed by the method of extreme difference analysis.The optimum combination of process parameters is obtained:the pouring temperature is 680?,the injection speed is 4.0m/s,and the preheating temperature of the die is 220?.Finally,production verification was performed based on the simulation optimized process parameters.The ADC12 aluminum alloy aluminum ingots are smelted and insulated to maintain a casting temperature of 680?.Then the die casting was preheated and the preheating temperature is 220?.Production verification was carried out according to the established production process.The produced die castings have clear outlines,smooth surfaces,and no obvious defects such as shrinkage porosity and shrinkage cavity at the key parts of castings.The final parts obtained by the subsequent processing are dimensionally stable and have no surface shrinkage,meeting the requirements for assembly and use.It shows that the mold design is reasonable,and the computer simulation technology combined with orthogonal test methods optimizes the process parameters and shortens the product development cycle.