Finite element modeling of electric current-activated sintering: The effect of coupled electrical potential, temperature and stress

A finite element model is developed to simulate three-way coupling of thermal, electrical and mechanical behavior of electric current-activated sintering. In addition to the direct simulation of the evolution of electrical potential and temperature in the system, the model is capable of simultaneously calculating the displacement fields and the stress distributions. Experimentally measured temperatures are found to be in excellent agreement with simulations. The displacement and stress distributions were found to depend on the material properties. In the copper system, owing to its large thermal expansion, the steady-state vertical stress has a gradient of 33% across the sample at a 1000 A current input (∼700 °C); the radial and angular stresses are significant and have larger gradients. The maximum shear stress analysis indicates high stress concentrations at the surfaces at the ends of plungers that are in contact with the spacers.