Lost foam casting manufacturers talk about the quality factors affecting coating castings

There are mainly three types of lost foam casting process conditions: foam model, dry sand, and negative pressure; the entire processing process has actually completed three types of copies. To get a flawless casting, it is important to have three copies done. The foam model copy will have defects such as deformation, incomplete white mold, poor surface polishing, overweight, etc. These defects have a profound impact on the quality of lost foam coating castings.

The Ductile Iron Lost Foam Investment Casting is mainly completed through specific process equipment, including five parts such as refractory materials, suspending agents, binder auxiliary additives, and media. Each part should be selected in full consideration of the thickness, shape, and production line standards of the casting.The defects in the performance of lost foam coatings mainly appear in the components of the coating and generally affect the hardness of lost foam castings in the following three categories:

1. The performance and viscosity of the adhesive in the coating ratio are not suitable, or the coating is too thin, the dry strength of the coating is low, and the wear resistance is poor. The coating cracks or falls off seriously during storage, drying, transportation, etc., which will cause foam. The appearance is deformed.

2. The particle size level of refractory materials is inappropriate; viscous gas occurs or the coating is too thick; the coating gas permeability is reduced; castings have pores, sediment-like cold separation, heavy skin, wrinkled skin, and other appearance defects.

3. The flame retardancy of the refractory material itself is low, so the high temperature strength of the cold insulation adhesive of the lost foam casting is poor or the paint absorption is poor, resulting in a large amount of sticky sand in the casting, which seriously endangers the surface quality of the casting.