Numerical Analysis Of Casting Defects Of Copper Alloy Water Meter Shell

In order to solve the problem of shrinkage cavity/porosity,misrun and other defects in the castings of copper alloy water meter shells,this study simulated the metal casting process of water meter shell with the Al type water meter in the Middle water meter co.,LTD and optimized its structure and casting process parameters,which will eliminate shrinkage cavity/porosity,misrun and other defects and reduce development cost.Through the analysis of the structure of the water meter shell,the 3D model and the finite element model were established by using Solidworks software as the modeling tool and ProCAST software as the casting numerical simulation tool,and then the numerical simulation was carried out.The numerical simulation of three kinds of processes including successive bottom note type without riser,stepped approach that tried to add riser and stepped approach with riser improvement was carried out.The filling sequence,temperature distribution,liquid distribution in the solidification process and shrinkage cavity/porosity distribution of three different processes were analyzed comprehensively and casting process of the copper alloy water meter shell were optimized.The simulation results show that the metal liquid can rise steadily during the filling process and the gas in the cavity can be smoothly discharged to avoid the defects such as the pores by bottom note type pouring.However,because of the chilling effect of the metal type,thin areas of casting is easy to advance curdle,thus blocking the filling of the metal;by means of the stepped pouring,when the filling capacity of the metal liquid was affected due to lower temperature,the metal liquid enters into supplement pouring gate on the top and then it joins the metal solution from the bottom,which leads to the lowest temperature in the middle of the casting and the incremental temperature gradient to both ends up and down;preliminary design of casting head has obvious feeding effect on the wall thickness of the casting,but did not eliminate shrinkage cavity/porosity.Through the optimization of the casting structure and riser,the volume of shrinkage cavity/porosity at the inlet was reduced from 0.68cm3 to 0cm3,and the volume of shrinkage cavity/porosity at the adjustment sleeve was reduced from 1.39cm3 to 0.22cm3.In the meanwhile,the volume of shrinkage cavity/porosity at seal ring was reduced from 1.32cm3 to 0.23cm3.Aiming at the process parameters of metal casting of copper alloy water meter shell,the orthogonal experiment was designed,and the casting temperature,casting time and mold initial temperature were selected as the main factors that influence the quality of castings.The simulation results show that the incidence of the casting quality of the castings of the copper alloy water meter is:pouring time>casting temperature>the initial temperature of the mold;Through the additional experiment of the three factors,it can be seen that the effects of three factors on copper alloy water meter shell present v formation.In the range of each factor level,there is a tendency in shrinkage cavity/porosity defects that reduces first and increases later,which gets the best casting process parameters.the casting temperature is 1040 ?,the casting time is 2s,the initial temperature of the mold is 150 ?.The correctness of the numerical simulation results of casting is verified by the actual processing of the A1 type water meter shell.The results showed that the surface quality of the copper alloy water meter shell is good and the defects such as insufficient pouring are avoided under the best process parameters.Through the observation of the section of the casting,it can be seen that the castings are tightly packed and no shrinkage cavity/porosit,porosity and so on.