НЕКОТОРЫЕ ОСОБЕННОСТИ РАЗРАБОТКИ ФОРМОВОЧНЫХ И СТЕРЖНЕВЫХ СМЕСЕЙ С ПРИМЕНЕНИЕМ БОРАТФОСФАТНЫХ СВЯЗУЮЩИХ

Abstract

In the practice of foundry production, it is known to use cores of phosphate cold-hardening mixtures (CMC), containing: aluminophosphate (APS), magnesium phosphate (MFS), aluminochrome phosphate (ACPS), magnesium aluminophosphate (MAPS), calcium magnesium phosphate (CMPS), chromophosphate (CPS) and boraluminophosphate (BAPS) and other binders [1-20]. The widespread use of metal phosphate binders (MPBs) is hampered by the fact that CBTs made on their basis have a number of disadvantages. In particular, cold-hardening mixtures prepared using an aluminophosphate binder (APB) and a magnesium phosphate binder (MPB) do not provide the mixtures with sufficient binding and strength properties. Regulation of such properties of molding and core mixtures as survivability, formability, crumbling, strength and some other properties occurs by changing the composition and content of binder compositions in the mixtures. It is known that boric acid and its salts exhibit adhesive-cohesive properties and the use of which as a modifier in the composition of thermal insulation, molding, and core mixtures improves their physical, mechanical and technological characteristics. It is also known that boric acid enters into chemical reactions with inorganic and organic substances to form complex compounds that exhibit more pronounced binding properties than boric acid. The purpose of the work is to improve the properties of aluminophosphate and magnesium phosphate cold-hardening mixtures using boric acid (H3BO3), borophosphoric acid (composition H3BO3•H3PO4) and borophosphorous acid (composition H3BO3•H3PO3) and their effect on the strength characteristics, crumbling and formability of the tested mixtures.