Silica Sol casting, also known as investment casting, is a precision casting process widely used in industrial manufacturing. It is particularly suitable for producing metal parts with complex shapes, high precision and high surface quality.
Making wax molds
First, using the investment injection molding technology, wax is injected into the mold to form a wax mold that is exactly the same shape as the final metal casting. This step is the basis of the entire process.
Mold tree
Next, multiple wax molds are combined together to form a "mold tree" so that multiple castings can be produced at one time. This step improves production efficiency.
Coating (shell making)
The mold tree is immersed in silica sol (a high-temperature stable solution) and sprinkled with refractory materials such as zirconium oxide or aluminum oxide powder. Repeat the coating and powdering several times to form a solid shell.
Dewaxing
The wax mold coated with the shell is heated to a certain temperature, and the wax mold melts and flows out, leaving an empty shell. This step is called the dewaxing process.
Baking the shell
The shell after dewaxing needs to be baked at high temperature to increase the strength of the shell so that it can withstand the impact of high-temperature molten metal during the casting process.
Pouring metal
Pour the molten metal (such as stainless steel, carbon steel, copper alloy, etc.) into the shell. The high-temperature metal liquid will fill the cavity of the shell to form the final shape of the metal part.
Shelling and cleaning
After the metal cools and solidifies, knock off the shell to expose the casting. Then carry out necessary follow-up treatments, such as cutting the gate, grinding, heat treatment, etc.
Inspection and finishing
After the casting undergoes strict quality inspections (such as dimensional inspection, surface inspection, non-destructive testing, etc.), it is subjected to finishing treatments such as machining and polishing to ensure that the final product meets the design requirements.