WETTABILITY OF ACTIVATED BY VARIOUS MEANS GRAPHITE BY WATER–BASED SYSTEMS

Abstract

The formation of a high-quality casting surface is a complex process, determined by the nature of an alloy filling, heating the mold, physicochemical and mechanical interaction of the melt with the atmosphere of the mold, in the contact zone material-mold. On the one hand, the filler of the antipenetration wash should not be wetted by alloys, on the other hand, to form properties in the liquid state, the filler should be well wetted by a solvent. At present, the most common solvent used in the antipenetration wash is water. The purpose of this work is to study wettability of graphite activated by various methods i.e. by water and water –based systems . In the course of the process it was found that activated GKM is wetted by water worse (wetting angle is 90–1200 depending on the method of preparing GKM than natural graphite (wetting angle of water is 550). It was revealed that activated graphite is better wetted by water-based binding systems: depending on the activation method (mechanical, chemical and chemical-mechanical) the wetting graphite angle by 10% LST solution decreases from 49 to 370; by 3.5% water bentonite slurry - from 69 to 500; by water-based binding system containing 10% LST and 3.5% bentonite - from 54 to 40º.