| Die-casting is a near net shape forming technology,which is widely used in aerospace,automobile manufacturing and other industries.With the rapid development of global industry,the proportion of aluminum die casting in the field of casting gradually increased.Die casting process is a very complex process,it is prone to appear wrap gas,oxide inclusion,cold traps,porosity,sticky mold,shrinkage etc in the process.However,in order to ensure the quality of the casting,enterprises often rely on the experience to repeatedly adjust and test the molds to deal with these defects;So resulting in the casting production cost increase and the production cycle extended,at the same time,the competitiveness of enterprises weakened.This paper was aimed at the problem of sticky mold,cold traps and a large number of shrinkage in the aluminum alloy magnetic motor cover during the process of the die casting,which resulted in the low qualification rate of the products.By adopting AnyCasting software to simulate the casting process,and combining with P-Q~2 technology and orthogonal test to get a production plan of the magnetic motor cover which contained that die casting machine and die-casting mold had a good matching degree,the design of mold structure was reasonable and die casting process parameters were optimal.So providing a new feasible path to solve the problem for the enterprise.The main contents were as follows:(1)By using P-Q~2 technology to study the die casting system under the original production plan of casting.It was found that the die-casting machine and the die-casting mold had low matching degree,and the requirements of changing the die-casting machine were put forward.Using numerical simulation technology to simulate the filling process and solidification process of the castings,and summarizing the specific reasons for the lack of castings.For the reasons,the structure of the mold was improved,and the matching between the renewal die casting machine and the improved die was evaluated by P-Q~2.(2)Simulation of castings of mold structure improved was carried out by AnyCasting software.The results showed that the flow of molten metal was smooth during the filling process,there weren’t cold traps in the process,the temperature field distribution of the solidification process was more balanced,the shrinkage of the thick location was improved,and the Sticky mold ratio of the improved scheme was reduced in the process.Then the push rod of the pushing mechanism of the improved scheme was redesigned,and obtained that the improved scheme adopted the push rod with the diameter of 8mm and the number of 39.At this time,each push rod stability checking showed reasonable.(3)By using orthogonal test method,how the alloy pouring temperature,mould preheating temperature and punch injection speed effected the shrinkage forming of magnetic motor cover casting was studied,and found that the pouring temperature had the greatest influence on the formation of shrinkage porosity,mould preheating temperature took the second place and punch injection speed was the least significant.Meanwhile,the optimum process parameters of the casting qua lity guaranteed were obtained by analyzing the test results: pouring temperature was 630℃,mold preheating temperature was 170℃,the injection speed was 2.1m/s.(4)Use the die that had been structure-improved to apply actual production of castings on the renewal die casting machine with the the best process parameters.The results were in good agreement with the simulation results.The cold traps defect on the casting surface was eliminated,the sticking rate was reduced,and the shrinkage of the thick part were reduced significantly,the overall quality of castings meet the requirements of enterprises. |
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