Introduction to the preparation of stainless steel precision casting coatings

Precision casting refers to the general term for obtaining precise size castings. Compared with the traditional sand casting process, the casting size obtained by precision casting is more accurate and the surface finish is better. It includes investment casting, ceramic mold casting, metal mold casting, pressure casting and lost foam casting.
The surface coating of stainless steel precision castings determines the surface quality of the castings. Therefore, the coating quality is required to be high, the silicon powder is fine, the coating viscosity should not be too high, and the sand removal should be fine. The coating of the reinforcing layer strengthens the shell and prevents damage to the shell. Therefore, coarse silica powder can be used, the coating viscosity is higher, and the particle size of sand removal is also larger.
Preparation method: first add a certain amount of dry material into the mixing tank, and continue mixing. Add powdered materials one after another. After adding, continue to stir for more than 15 minutes until the powdery substance becomes a uniform suspension, and then use it after standing for a period of time. The coating generally adopts the dipping method.
The paint can be divided into a surface layer and a reinforcement layer (ie, the second layer and subsequent layers) according to the difference of the shell layer. The refractory coating for stainless steel precision casting is a suspension made of powdered refractory materials (silica fume, corundum powder) and ethyl silicate hydrolyzate or water glass solution.