The three groups of pouring test temperature data of ringduring solidification are as follows: Figure 1, figure 2 and figure 3 show the measured temperature data of thermocouple of ring sand casting with inner / outer radius ratio of 30mm / 80mm, 50mm / 100mm and 70mm / 120mm respectively. TCN (n = 1 ~ 8) represents the measured temperature of thermocouple n, Tc1 and TC5 represent the surface temperature of sand casting at the casting / sand mold interface and the casting / sand core interface respectively, TC2, TC3 and TC4 represent the thermocouple temperature data in the sand mold 6mm, 14mm and 22mm away from the casting / outer sand mold interface, and TC6, TC7 and tc8 represent the thermocouple temperature data in the sand core 6mm, 14mm and 22mm away from the casting / sand core interface, The temperature measurement data of the first 6000s are selected in the figure to ensure that the data can be better compared.
By observing figures 1, 2 and 3, it can be seen that the temperature field change curves of outer sand mold and inner sand core of several groups of aluminum alloy ring sand castings with different sizes. When we ensure the same pouring temperature of 705 ℃ and the ambient temperature of about 25 ℃, and ensure the same initial temperature, it is not difficult to see that at the initial stage of pouring the metal liquid into the mold cavity, the temperature difference between the metal liquid and the sand mold and sand core is large. The metal liquid is cooled by the sand mold and sand core, the temperature drops sharply, and the temperature of the sand mold and sand core rises rapidly. Affected by the geometry and size of sand mold and sand core, there are great differences in the temperature field between the inner sand core and the outer sand mold of liquid metal. The temperature field of the outer sand mold is lower than that of theduring the whole solidification process, while the temperature of the inner sand core will reach saturation at a certain time, and then higher than that of the sand casting; When the thickness and height are the same, and with the increase of the inner and outer radius of the sand casting, the temperature saturation time of the sand core will be gradually delayed. In several groups of data, the vertical angle analysis data of sand mold and sand core temperature field can also be seen that the change of outer sand mold and inner sand core temperature field is affected by geometry. Compared with the change of outer sand mold temperature field, the temperature difference in inner sand core temperature field in the later stage is very small; With the increase of the size of annular sand mold casting, the change law of sand mold temperature field at the outer interface of annular sand casting is basically the same as that of flat sand casting.