Research On Investment Casting Technique Of Large Complex Thin-Walled Magnesium Alloy Satellite Stents

In this paper,the magnesium alloy bracket of satellite belongs to large thin walled frame structure,because of the liquid metal filling process is so long,it is very difficult to casting,the casting defects such as shrinkage,shrinkage cavity,is easy forming after the casting.In recent years,with the development of aerospace technology,it becoming more and more popular in aircraft structures,such as lightweight and structure function integration,gradually toward thin wall castings,the structure becomes complication and function integration in the direction of development.To large complex thin-walled magnesium alloy bracket of satellite,this paper not only demands the quality of the casting itself metallurgy is higher,and requires high precision,the traditional sand mold gravity casting technology is more and more difficult to meet the dimensional precision of high precision casting requirements.Based on the space with large casting magnesium alloy satellite stents as the research object,through 3D printing technology and the investment casting technology using the wax models of production,through low pressure casting process were studied.In magnesium alloy bracket of satellite,before the actual casting production,using numerical simulation software Pro CAST,the low pressure casting filling and solidification process was simulated,based on the analysis of the casting process conditions of actual production application,the combination of casting filling and solidification temperature field,flow law predict casting defects,analysis the reason its forming and preventive measures,casting of magnesium alloy bracket of satellite system optimization design,to determine the optimal casting solution,finally through production verification,to obtain the qualified castings.Magnesium chemical activity is very strong,and react with oxygen extremely easily in the air,it will cause burning,in addition,the reaction during pouring between magnesium also easy,resulting in a decline in the surface quality of the castings.In the various casting methods of magnesium alloy,the low-pressure casting can smooth the whole filling process,and it is guaranteed that the solidification of the solidification process can be certain pressure,so that the whole pouring system can solidify in sequence.These characteristics of low pressure casting reduce the slag of magnesium alloy in pouring process,which makes the structure and performance of the castings obviously improve.In this paper,the different casting process of magnesium alloy casting was comprehensively considered,and the casting process of magnesium alloy satellite support was determined by low pressure melting die casting process.Before the actual production casting,CAE simulation technology is important.According to previous production experience of casting process parameters,such as setting,after a lot of development work,to determine the final process parameters,the efficiency is very low.With the rapid development of society,such casting production mode is increasingly unable to meet the requirements of quality,performance and so on.The promotion and application of CAE casting has great economic and social value for the whole casting industry.The casting simulation software variable,this article use’s popularity in the foundry industry and have high esteemed finite element simulation software Pro CAST,filling the solidification process of magnesium alloy bracket of satellite analysis of temperature field,flow field is simulated,and the shrinkage defects of magnesium alloy bracket of satellite has carried on the reasonable forecast,thus effectively improve the accuracy and reliability of the casting process.Finally,through the analysis of different gating system simulation results,select the most optimal casting process of magnesium alloy bracket of satellite development work,and the pouring out of the magnesium alloy bracket of satellite post-processing analysis,draw the conclusion: 3D printing technology combined with investment casting technology manufacturing shell,using low pressure casting process for pouring,and carries on the reasonable design of gating system,can produce qualified quality large complex thin-walled magnesium alloy bracket of satellite,for large complex thin-walled parts of aeronautics and astronautics,and other similar castings production has a certain guiding significance.