Denis et al. Systematically studied the interface heat transfer behavior between aluminum alloy and mold shell in investment casting process, and studied the influence of various parameter errors on the calculation results of interface heat transfer coefficient. Shao Heng et al. Measured the temperature change of the mold shell and the casting in the process of investment casting through experiments, and calculated the interface heat transfer coefficient between the industrial pure aluminum casting and the mold shell in the one-dimensional heat transfer model by using the nonlinear estimation method. The interface heat transfer behavior between the casting and the mold shell in the process of investment casting was systematically studied. The analysis results show that: in the early solidification stage, the interface heat transfer coefficient between the casting and the mold shell is higher The results show that the heat flux is basically unchanged, but the interfacial heat transfer coefficient increases with the decrease of the temperature difference between the casting and the shell surface; in the middle stage of solidification, the interfacial heat transfer coefficient decreases linearly with the increase of solid fraction; in the late stage of solidification, the interfacial heat transfer coefficient decreases very slowly.
Dour et al. Designed a non immersion probe to realize temperature measurement. The probe used a non-contact infrared thermocouple. The heat transfer behavior of the interface between Al-12% Si alloy casting and H13 mold during die casting was studied by using the probe. It is found that the peak value of the heat transfer coefficient of the casting die interface can even reach 47000 w under the specific die casting process conditions In addition, they also found that only the initial mold temperature and high speed have a greater influence on the heat transfer coefficient of the casting mold interface, while the slow speed, casting pressure and pouring temperature have a smaller influence on the heat transfer coefficient of the casting mold interface. Hamasaiid et al. Systematically studied the influence of different die-casting process parameters on the heat transfer coefficient of the casting die interface through a large number of die-casting experiments. They got a similar conclusion with dour et al.
Guo et al. Systematically studied the interface heat transfer behavior of die casting process through experiments, and gave the relationship between the interface heat transfer coefficient and solid fraction and solidification rate
(1) Fast rising section. When the heat transfer coefficient of the casting die interface reaches the peak value, the increasing trend of the heat transfer coefficient of the interface slows down obviously. At this time, the heat transfer coefficient of the casting die interface fluctuates up and down near the peak value or begins to decline slowly after it reaches the peak value.
(2) High value maintenance stage. At this stage, the heat transfer coefficient of the casting die interface changes little. The change process of the interface heat transfer coefficient shows that the applied pressure makes the interface maintain a good contact state and ensure good heat transfer, but compared with the whole clamping stage, the time span is still small.
(3) Rapid decline stage. In this stage, with the solidification process and the formation of solidification shell, the casting pressure can not be effectively transferred to the casting. In addition, with the continuous cooling of each casting unit, the solidification shrinkage of the casting is larger, and the interface contact gradually deteriorates, which makes the interface heat transfer coefficient decrease faster than the previous stage.
(4) Low value holding stage. At this stage, the value of the interfacial heat transfer coefficient has been reduced to a relatively small level, and it does not change much in the subsequent cooling process. This stage represents the heat transfer state of the casting when the solidification is basically completed. At this time, the contact tightness between the casting and the mold is greatly reduced, and the small heat transfer coefficient also fully illustrates this point.