INCREASING THE HYDROPHILICITY OF THE SURFACE OF CASTING MODELS WHEN APPLYING A PRIMER LAYER OF CERAMICS WITH A DEVELOPED SURFACE

Abstract

For the manufacture of metal parts of complex shape, the most promising method is casting according to smelted or burnt models. As a smelted material, a complex composition of wax with other organic compounds is used, characterized by high constancy of physico-chemical and mechanical properties, since the accuracy of multiple reproduction of critical parts, for example, the blades of a turbojet engine, depends on it. The wax model is necessary for growing a ceramic shell around it, the accuracy of which is crucial for obtaining a high-quality casting. Since the surface of the wax model is hydrophobic, and the ceramic suspension applied to the model is created on a water basis, a critical factor in the shell manufacturing technology is the ideal wettability of the model surface by the suspension applied to it. Improvement of wettability can be achieved not only by introducing special surfactants into the aqueous phase, but also by changing the properties of the wax surface itself, i.e. giving it the properties of hydrophilicity. The paper presents a method of physical modification of the wax model surface, which consists in applying a thin layer of ceramic powder on it, which is well wetted with aqueous ceramic suspensions.