Doroshenko V. Theoretical and technological foundations for the production of sand molds from dry dispersion fillers for the production of lightweight cast structures.

The thesis is devoted to the development of theoretical foundations and technologies of molding from sand mixtures in the preparation of molds with different thermophysical characteristics, since the condition for obtaining castings with the specified structure and properties is the control of the intensity of the heat dissipation in the mold. Based on the concept of the effect of the construction of the casting pattern with two fluid media: the metal that is poured, replaces the gasification pattern and fills the casting cavity, and the sand environment around the pattern, creates methods for the physical, mathematical and computer design of lightweight porous metal products by inheriting the resource-saving nature structures, modern natural science. When creating the technology of casting on ice patterns, mathematical models of their shaping in the form of formulas for calculating the characteristics of their production from liquid-mobile compositions by cooling, crystallization, supercooling, freezing in various media and depending on the geometric shape of such mono-, multilayered and reinforced single patterns are proposed. Experimental data on the kinetics of freezing and bending strength are obtained as a function of the temperature of the ice patterns. The conditions for the formation of a quasi-liquid layer on the surface of such patterns are established, and the electric charge inherent in it is used to create and apply powder non-stick and sealing coatings of ice patterns. Methods of additive molding processes for producing sand products with deformation have been developed, and sandy molds have been obtained with differential strength when mixing materials as disperse systems with cold curing of the resulting molding mixture, combining molding with computer control, cryotechnology, consolidating sand mixture with inorganic binders and the possibility of it regeneration.