Solidification Simulation Of ZM6 Receiver And Process Optimization

Aviation receiver of magnesium alloy is characterized to have complex inner structure. In casting process, it tends to form defects that are hard to be removed. To achieve the air receiver with good quality, many sets of multi-mode mold, measuring utensil and the cold iron are needed. Moreover, the whole casting procedure is long. Therefore, before the real producing, numerical simulation should be carried out to predict the solidification sequence and optimize the casting parameters. The final aim is to improve the quality and product yield.In view of the above reasons, AnyCasting software is hired to calculate the filling and solidification process of cast magnesium alloys. Solidification defects such as macro-shrinkage and porosity are numerically predicted. Influences of casting parameters upon the formation of defects are discussed. The optimization of parameters is provided.The Case-1 is determined according to the former experience, and the numerical simulation of ZM6 receiver and process optimization are carried out based on Case-1. Case-1: the simulated results of ZM6 alloy show that many defects are formed in the casting body due to that the interdendritic liquid feeding is prohibited. Case-2: based on the results in Case-1, some feeders are added. The calculated results show that a great part of defects is transferred to the feeder. However, there are still some porosity in the casting body, as the riser cannot exert its fill shrinkage effect fully. Case-3: on the basis of the results in Case-2, iron-chill is used to achieve a good result. Calculations show that combination of feeder and iron-chill can effectively improve the quality of casting. It is obvious that the formation of defects is nearly suppressed. Case-4: to predict the real casting process, the mold-filling system is designed and the filling course is simulated. It shows that a smoothly filling pattern is due to a higher feeding velocity, and the design of mold-filling system is reasonable. Moreover, the initial temperature field is uneven as a higher feeding velocity creates a larger temperature gradient at some position. This may accelerate the local formation of defects. A lower feeding velocity increases the total solidification time which favors the formation of coarser structure. Therefore, the optimized feeding velocity is 0.6m/s. Under this condition, a uniform temperature field is achieved and the casting defects are eliminated.By means of the AnyCasting software, the validity of feeder and iron-chill is forecast. The optimized combination of parameters is pouring temperature 770℃and feeding velocity 0.6m/s.