Lost wax investment casting process
The investment casting process is to make a model with wax, wrap a layer of refractory materials such as clay on its surface, heat it to melt and flow out the wax, thereby obtaining an empty shell formed by the refractory material, and then pour the metal into the empty shell after melting. After the metal is cooled, the refractory material is broken to obtain a metal mold. This metal processing process is called precision casting, also known as investment casting or lost wax casting. The lost wax method can be used to cast very complex metal parts. The material can be stainless steel or copper alloy, aluminum alloy, carbon steel and so on.
Investment casting Application
Precision investment casting is used in almost all industrial sectors, especially electronics, petroleum, chemical, energy, transportation, light industry, textiles, pharmaceuticals, medical equipment, pumps and valves.
Lost wax method casting process
1. First of all, we must make a wax mold. The wax mold has a wax injection machine to melt the casting wax. At a certain wax temperature, a certain wax injection pressure is used to inject the flowing liquid wax into the cavity of the mold. After the wax has cooled and solidified, take out the wax mold and simply repair the defects of the wax mold, or bond different wax molds to obtain a more complex casting wax mold.
2. The tree formation process is simply to glue the already made wax model to a wax tree, which is the channel for the molten metal during casting.
3. After the tree formation process is completed, the wax mold is shelled. Generally, high temperature resistant materials such as silica sol or hydrosol are used to make the slurry. The upper shell should be dried continuously, then the slurry is dipped in the slurry, and some particle size Very small refractory zircon sand increases the strength, and the shelling process is repeated several times until the shell thickness reaches a certain requirement.
4. The process of boiling wax: Put the wax mold with the upper shell in the industrial pressure cooker to boil or steam, so that the wax melts and flows out of the shell, leaving only the outer shell. The wax that flows out can be recycled after dehydration.
5. Shell sintering: Put the shell into the furnace and sinter the shell at high temperature to make it reach a certain degree of refractoriness and strength.
6. Casting. Once the sintered shell is taken out, it should be cast immediately.
After the casting is completed, wait for the molten metal to cool and solidify, and the casting is basically completed. The remaining steps are to smash the refractory material of the shell to obtain the group tree of the metal casting, and then cut or saw the metal parts from the group tree. Then surface treatment and finishing are performed on the resulting castings.