Temperature and electric potential fields of an interface crack in a layered thermoelectric or metal/thermoelectric material

The interface crack problem in a layered thermoelectric or metal/thermoelectric material subjected to thermoelectric loadings is studied based on the nonlinear governing equations and complex variable method. The electric impermeable and heat semi-permeable crack boundary conditions are adopted. Explicit and closed-form solutions of temperature and electric potential on the interface crack surfaces, and crack tip thermoelectric fields are obtained. The influence of crack thickness to length ratio and thermal conductivity of air inside the crack on electric current density and heat flux intensity factors at crack tip is discussed. It is found that electric current density and heat flux intensity factors at the interface crack tip between metal interconnector and thermoelectric material are much bigger than those in homogenous or layered thermoelectric material. This explains why the failure (or microcrack initiation) of a thermoelectric generation/cooler element always appears at the interface between the metal electrode and thermoelectric material.