THERMOMECHANICAL BEHAVIOUR OF MAGNESIA-CARBON REFRACTORIES

Abstract

An experimental investigation of the thermomechanical behaviour of pitch and resin bonded magnesia-carbon refractory materials has been carried out within the temperature range 20-1500°C by tension, compression, and three point bend tests. At room temperature, both types of material exhibited a non-linear, quasi brittle behaviour similar to that of concrete. The non-linearity is ascribed to microplasticity and degradation processes and is time dependent. The mechanical characteristics of the pitch binder refractory were found to be superior to those of the resin binder material. After the physical-chemical transformations which occur below 500-600°C, the non-linear behaviour of the refractories is primarily governed by degradation and plasticity mechanisms. Time effects were observed at different temperatures during decomposition of the binder and at temperatures above 1000°C. The data established form a basis on which to facilitate the development of more accurate physically based thermomechanical models.