Preheat the mold with natural gas flame, then spray paint on the surface, and raise the temperature to about 300 ℃. Pour the melted ZL102 alloy liquid into the mold, take out the sand casting after solidification and forming, and check the surface quality and size of the casting.
Use UT302A infrared thermometer to measure the preheating temperature of the metal mold and observe the relationship between the temperature and the defects of the sand casting. See Table 1 for the results. It can be seen that 300~350 ℃ is appropriate.
| 270 | 300 | 330 | 350 | 360 | 390 |
| Local cold shut | None | None | None | Slight surface porosity | Surface porosity |
The XCZ-101 dynamic coil thermometer and thermocouple are used to measure the temperature of molten aluminum. The relationship between pouring temperature and sand casting defects is shown in Table 2. It can be seen that 680-710 ℃ is the appropriate pouring temperature range.
| 640 | 660 | 680 | 700 | 720 | 740 |
| Underpouring | Local cold shut | None | None | Basically free of defects | Air hole on inner cavity surface |
See Table 3 for the results of the cooling time test of the mold. It can be seen that 70~90 s (summer) or 40~60 s (winter) is a suitable cooling time range for sand castings after pouring.
| Mold retention time in summer/s | Mold retention time in winter/s | Casting defects |
| 60 | 30 | Hot cracking |
| 70 | 40 | Basically free of defects |
| 80 | 50 | Basically free of defects |
| 90 | 60 | Basically free of defects |
| 100 | 70 | Difficult to take out or deformed or damaged |