For the interface heat transfer with pressure, there is a definite relationship between the interface heat transfer coefficient and the interface pressure and temperature. Therefore, it is important to establish the relationship between the heat transfer coefficient of squeeze casting die interface and the interface pressure and temperature.

A large number of quantitative data of interface heat transfer coefficient, interface pressure and interface temperature were obtained by squeeze casting experiment. On this basis, the micro contact mechanics model is used to study the relationship between the heat transfer coefficient of squeeze casting die interface and the interface pressure and temperature. The research ideas are as follows: through micro geometry analysis and micro mechanics analysis, the relationship among interface pressure, interface temperature and interface spacing is established; through micro heat transfer analysis, and using the data obtained from squeeze casting experiment, the relationship between interface heat transfer coefficient and interface spacing is established; and then the relationship between interface heat transfer coefficient and interface pressure and interface temperature is obtained. In addition, after the interface pressure is reduced to zero, the relationship between the interface heat transfer coefficient and the interface temperature is established by fitting the experimental data.

Based on the theoretical analysis and the quantitative data obtained from squeeze casting experiments, the relationship between the interfacial heat transfer coefficient and the interfacial pressure and temperature is studied

(1) Based on the theory of micro geometry / contact mechanics, a model was established to describe the interface heat transfer between squeeze casting and die. The model can quantitatively describe the relationship between the interface heat transfer coefficient and the interface pressure, temperature and other factors by considering the contact stress, effective heat transfer area, material mechanical properties and relevant thermal parameters between the casting and die on the micro scale.

(2) The experimental results are in good agreement with the model results. The model can accurately calculate the interface heat transfer coefficient on the premise of knowing the interface pressure and temperature.

(3) Through data fitting method, the model of heat transfer coefficient after the disappearance of interface pressure is established.