Mechanical destruction character of sand-sodium-silicate mixtures structured in steam-microwave environment

Abstract

Purpose. There were nature investigation and description development of sand-sodium-silicate mixtures mechanical destruction nature changing according to the time of their structuring in steam-microwave environment. M ethodology. Structured mixtures tensile strength has been determined on LRu-2e model device in accordance with GOST 23409.7. Sand-sodium-silicate mixtures fracture surfaces structure has been studied using scanning electron microscope SEM-106I model at accelerating voltage of 20 to 30kV and probe current of 4A to 30A in secondary electrons with probe diameter of 1000 to 200nm. Sand-sodium-silicate mixtures destruction mechanism description development has been carried out based on analysis results, comparison, exclusion and generalization of known and obtained by the authors of this work experimental results and theoretical data, published in open scientific sources devoted to present analysis subject. Findings. Regardless of sodium silicate solute content in structured sand-sodium-silicate mixture, its destruction nature depends on steam-microwave treatment time, which changes from adhesive to combined and cohesive with treatment time increasing. According to fracture mechanism description developed, transition from adhesive to cohesive fracture mechanism is caused by the time dependence character of both adhesive strength in quartz-sodium-silicate-solute system and cohesive strength in sodium silicate solute in mixture cuffs increasing. At the same time, sodium silicate solute cohesive strength changing over time during microwave treatment is of an extreme nature and, obviously, caused by sodium silicate from sodium silicate solute polymerization degree during its dehydration. Originality. For the first time, description of sand-sodium-silicate mixtures mechanical destruction changing nature devoted to their structuring in steam-microwave environment time has been developed. Practical value. Data obtained make it possible to expand the understanding about sand-sodium-silicate molds properties and their destruction mechanism under mechanical influence, to evaluate the method of structuring in steammicrowave environment possibilities, to purposefully choose research directions and practical actions in terms of structured sand-sodium-silicate mixtures properties level regulation