The critical size of brittle solid materials and the measurement of their surface tension

Abstract

AbstractThe relationship of the energy required to break a particle or a particulate material vs. particle size has been studied by many researchers. On the one hand, mineral processing engineers, who are interested in the specific energy (in joules per cubic meter or joules per kilogram) required for grinding, almost agree that it is inversely proportional to the particle size, although they might disagree on the type of the relationship. On the other hand, building and structural engineers, who are mainly interested in the strength of materials (in newtons per square meter or pascals), they almost agree that at the size range of the elements used, their strength depends on the quality of the material rather than its size. The present article shows that both groups of engineers are right about the size range of the bodies used by each one. However, there is a critical size that determines the fracture behavior of a brittle material. The definition of the critical size can be used to understand the practical results obtained as well as to measure the surface tension of the tested materials.