ELECTRICAL AND THERMAL TRANSPORT MODELS FOR ANALYSIS OF REINFORCED COMPOSITES.
Abstract
The relationship between the electrical and thermal transport properties on the one hand, and the structure properties of a composite system on the other, is qualitatively demonstrated and different theoretical models are presented to describe the transport behavior. The simple approach of assuming that transport is similar to a series and parallel arrangement of equivalent resistors is developed for a variety of composite configurations and for completely general choices of the individual parameters and volume fraction of each constituent. The calculations are extended to include the effects of interdiffusion between the dissimilar materials, as would be expected following prolonged exposure to high temperatures. In addition, the semiquantitative model is shown to be adaptable to the analysis of the effects of sintering on the transport properties and is shown to be an effective tool for following the progress of void depletion. The calculated values are compared, for one particular configuration, with experimental studies on two-dimensional voids, as well as with more exact methods of computing effective conductivities based on solutions of Maxwell's equations. It is further shown tat while quantitative values are somewhat different for the two methods of calculation, particularly in extreme cases, the simpler method is suitable for further detailed analysis of changes in properties as functions of environment-induced changes in the intrinsic arrangement of the materials and the effects of diffusion. A comparison of the present approach with the results of other investigators is shown, and a critique of previous methods is presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 26, 1966
- Accession Number
- AD0486667
Entities
People
- Jules J. Duga
Organizations
- Battelle Memorial Institute