Estimation of the electrical conductivity of TiB2/Al composites by using image analysis

Abstract

The goal of the present work was developing the software for calculating the electrical conductivity of aluminum-based particle-dispersed composites by using the actual microstructure images and by performing conduction simulations. However, the electrical conductivity calculated using the microstructure image was supposed to be not equivalent to the electrical conductivity measured by using any of the existing experimental methods, because the microstructure image is a two-dimensional source of information, although the experimental conductivity is obtained from three-dimensional microstructures. Therefore, the statistical relationship between three- and two-dimensional electrical conductivities was investigated by performing the conduction simulations. The electrical potential distribution in the steady state was calculated by using the finite volume method, and the electrical conductivity of the composites was evaluated. The average electrical conductivity of two-dimensional cross-sections was lower than that of a three-dimensional cell, and the difference increased with increasing volume fraction. When the difference between the matrix and reinforcement electrical conductivities was small, the difference between the two- and three-dimensional electrical conductivities was small as well. The difference between the two- and three-dimensional electrical conductivities was constant for all volume fractions even when dispersibility changed. A correction for converting the two-dimensional electrical conductivity to the three-dimensional electrical conductivity was suggested. The electrical conductivity of Al/TiB2 was evaluated from the actual microstructure image by performing the conduction simulation.

Keywords

• composite materials
• electrical conductivity
• image analysis
• particle dispersibility
• finite volume method