Revealing thermomechanical properties of Al2O3-C-SiC composites at sintering

Abstract

The processes of semi-dry pressing of corundum-graphite silicon-carbide materials and the influence of the content of silicon carbide and graphite on the strength characteristics of composites were studied, and the optimal composition of the charge with high physical and mechanical properties has been determined. The most effective antioxidant additives to increase the physical and mechanical properties of carbon-containing composites have been identified. The temperature dependences of the compressive strength of the Al2O3-C-SiC composite have been studied. The main factors of the effect of antioxidant additives on the value of weight loss upon heating to 1000°C of modified corundum-graphite silicon car-bide-containing materials obtained on the basis of the developed basic Al2O3-C-SiC composites have been established. The main indicators of the increased stability due to the introduction of various effective binders and antioxidant additives are studied, the mechanism of action of which is manifested both due to the formation of a liquid phase enveloping graphite flakes during sintering, and the synthesis of carbon-containing compounds — silicon carbide, aluminium carbide, aluminium oxycarbides.