1. Mold making process
Mold making is the initial step in investment casting and the foundation for ensuring casting precision. Using easily fusible wax, a wax model is pressed into shape using a mold, perfectly matching the final product. This ensures the wax model is dimensionally accurate, has a smooth surface, and adheres seamlessly to every detail of the finished product. For castings with complex structures, the wax model needs to be disassembled and then reassembled into a module to prepare for the subsequent shell-making process. This step is one of the key differences between investment casting and ordinary casting.
2. Shell making process
The shell-making process requires multiple treatments of the wax model assembly, the core of which is to create a robust refractory shell. The wax model assembly is repeatedly immersed in a fine refractory coating, then evenly sprinkled with refractory sand. After multiple coatings and natural drying, a dense, high-temperature refractory shell layer is formed. This shell layer must possess sufficient strength to withstand the high-temperature impact of the subsequent molten metal, while ensuring a smooth inner wall to guarantee the surface quality of the casting.
3. Pouring process
Casting is the core forming step in investment casting. First, the refractory shell mold is fired at high temperature, causing the wax model inside the shell to completely melt and flow out, forming a cavity that matches the shape of the finished product. Then, qualified molten metal is poured into the cavity at an appropriate speed and temperature. Gravity allows the molten metal to fill the entire shell mold, fully replicating the details of the inner wall of the shell mold. After the molten metal cools and solidifies, the casting is basically formed.
4. Cleaning and Repair Stage
Cleaning and finishing are the final steps in investment casting, aiming to bring the casting to the specified standards. After the casting has completely cooled, the outer refractory shell is broken, and any remaining refractory material and risers are removed from the surface. Further processing, such as grinding and polishing, eliminates minor surface imperfections and calibrates dimensional accuracy, ultimately yielding a finished investment casting that meets the requirements and can be directly adapted for subsequent assembly.
If you would like to learn more about Stainless Steel Investment Casting, please contact Wuxi Philloy Machinery for further consultation. Our professional team provides 24/7 service.
