Cracking and thermal shock resistance of a Bi₂ Te₃ based thermoelectric material

Thermoelectric materials can realize the mutual conversion between thermal energy and electric energy. The materials are brittle in nature and prone to damage by thermal shock. Naturally, it is very necessary to analyze the fracture properties of thermoelectric materials. This paper studies a Bi2Te3 based thermoelectric material plate subjected to one-dimensional temperature load along its thickness direction. The associated temperature and stress fields in steady and transient states are solved in analytical forms. The stress intensity factor histories are acquired by the weight function method and the corresponding thermal shock resistance of the material plate is investigated. It is discovered that the transient stresses are much bigger than steady stresses. The maximum stress intensity factor increases with the increasing of the thickness of the plate. The value of thermal shock resistance is enhanced when the plate is thinner. An empirical formula for the thermal shock resistance is explored, which can be conventionally used by the materials scientists and engineers to predict the maximum temperature under which the material can sustain without failure