THERMAL SHOCK OF REFRACTORIES

Being brittle and having low thermal conductivity, refractories suffer damage andsometimes fail in service as a result of thermal shock. while the approach of those making finegrainedtechnical ceramics is to make their products sufficiently strong to withstand thermalstresses; the refractory technologist is more cunning. he uses, often little known, devices toprovide resistance to thermal shock that minimise but do not eliminate damage to the component.in this paper the basic equations ofthermal conduction and elasticity are presented andfollowedby some immediate results that should guide the designer ofcomponents subject to severe thermalenvironments. the influence of size and shape of the refractory components is then discussedalong with ways in which refractory producers can engineer the thermal and mechanicalproperties. in particular, the methods used to tailor fracture behaviour to optimise the thermalshock resistance are treated in some detail.