Thermal Shock Behaviour of Brittle Materials

Abstract

WE have been investigating the thermal shock behaviour of some glasses and other materials, using an argon plasma jet, as a preliminary part of an investigation into the thermal shock behaviour of brittle materials. The plasma jet was used in this investigation since it affords an easy and reliable method of producing very high heat transfer-rates of the order of 400–500 cal./cm.²sec. In the present experiments the samples, in the form of disks ½ in. thick and $\frac{7}{8}$ in. diameter, could be shocked every 2 sec. for up to 1,000 times, the shock itself lasting about 0.16 sec. Under these conditions it was possible to obtain surface melting on such materials as soda glass, borosilicate glass and an electrical porcelain.