Advanced Technologies of Manufacturing Readily Removable Cores for Obtaining High-Quality Castings

Abstract

The work investigates the physical, mechanical, and technological properties of mixtures to manufacture cores in a foundry. The filler is technical salt, the binder is an aqueous solution of sodium silicate, and the hardener is a solution based on propylene carbonate on a silicate basis. These rods are used to make internal surfaces in thin-walled castings. The work proposes a new method of manufacturing cores based on cold-hardening mixtures (CHM), which harden at room temperature. The planned experiment was chosen as the basis for modeling the properties of the mixture. The following parameters were chosen as optimization parameters: compressive strength, friability, and durability. According to the developed mathematical models, the mixture composition was optimized. The optimum binder content is 4.0 to 6.0%, and the hardener content is 0.3 to 0.4%. A technological process of preparing CHM for readily removable salt cores has been developed. As a result, the surface quality of the internal surfaces of castings improved. The cycle of core production was reduced, and the casting cleaning costs were reduced due to the elimination of the decoring process; environmental safety of the technological process was provided to the use of non-toxic materials.