The so-called precision investment casting process is simply to use fusible materials (such as wax or plastic) to make a fusible model (referred to as investment or model), apply several layers of special refractory coatings on it, and dry and harden it to form After an integral mold shell, use steam or hot water to melt the model from the shell, then put the mold shell in the sand box, fill it with dry sand molding around it, and finally put the mold into the roasting furnace for high temperature roasting (If a high-strength mold is used, the mold shell after demolding can be directly fired without modeling). After the mold or mold is fired, molten metal is poured into it to obtain a precision casting.
Operation procedure of precision investment casting process:
- 1. Take out the wax cylinder from the heat preservation tank and install it on the double-station hydraulic wax injection molding machine. The air and hard wax in the wax should be removed before use.
- 2. Position the mold on the worktable of the injection molding machine, check whether all the cores of the mold are positioned correctly, and whether the wax injection port of the mold is aligned with the injection nozzle of the injection molding machine.
- 3. Check whether the mold opens and closes smoothly.
- 4. Open the mold and spray a thin layer of parting agent.
- 5. Adjust the time cycle of the injection machine in accordance with the technical regulations, including injection pressure, injection temperature, pressure holding time, cooling time, etc.
- 6. At the end of each cycle, the core, open the mold, carefully take out the wax mold, and put it into cooling water or storage tray as required. Note that wax models with the following defects should be scrapped:
- A. Part of the wax mold is bulged due to air entrained in the mold material; B. Wax mold has missing corners in any part; C. Wax mold is deformed and cannot be easily repaired; D The size does not meet the requirements.
- 7. Remove the remaining mold material on the mold. Note that only a bamboo knife can be used instead of a metal blade to remove the remaining mold material to prevent damage to the mold cavity and parting surface.
- 8. Close the mold and press the wax mold next time. After each shift or after the mold is used, use a soft cloth or cotton swab to clean the mold, and fasten the mold with screws.