Study On Interface Heat Transfer Coefficient During Solidification Of Metal Mold Casting

Along with the successful application of computer technology in casting process, an accurate boundary parameter can be used to simulation for guiding the practical production. A numerical simulation of casting solidification process is the core content of casting CAE, and predict casting defects and its organization, the basis of mechanical properties. Accuracy of interface parameter directly affects the reliability of the casting simulation, which affects the casting CAE to guide production, is more impossible to predict mechanical properties and casting.Casting A356 aluminum alloy is selected as casting material. Under the condition of a variety of solidification, temperature measurement experiment is carried out. Based on the mathematical model of the inverse problem, using finite element analysis software Procast, set collecting in the process of experiment data as input parameters. Under the condition of gravity foundry, temperature field of metal mold casting solidification is simulated analysis of temperature field casting- mold interface heat transfer coefficient. Get the following main conclusions:(1)Changes of the interfacial heat transfer coefficient in the solidification process can be divided into three stages: rapid increase stage, rapid decline stage and maintain low stage. When the pouring complete, the interfacial heat transfer coefficient reach the maximum value rapidly. With the thickening of the solidification layer and the exacerbating shrinkage, interfacial status become partial contact from perfect contact gradually. The expansion of the air gap lead to a rapid decline of the interfacial heat transfer coefficient. In the end of the solidification, the contact status between cast and mold become stable, and the interfacial heat transfer coefficient become stable gradually.(2)By comparing the interfacial heat transfer coefficients obtained from the experiment without coating and the experiment with coating, it can be found that the use of coating leads to a reduction in the interfacial heat transfer coefficient value and a lengthening in time for it to reach the maximum value.(3)In this paper, the qualitative analysis of solving inverse heat conduction problem some difficulties. Solve the large amount of calculation, nonlinear, discomfort. Design temperature measurement scheme(temperature measuring system). Two factors of affecting the interface heat transfer coefficient are coating and pouring temperature, four groups of temperature measuring experiment is designed. Basing on the reverse analysis method is established to solve in the process of casting aluminum alloy and the mathematical model of the interface heat transfer coefficient of metal mold. Then obtain reverse interface heat transfer coefficient by the accurate temperature field measured through experiment.