CHANGE IN THE ELECTRICAL-RESISTANCE OF POROUS POWDER AND FIBER COMPACTS DURING HEATING AND COMPRESSIVE LOADING

The effect of hearing at a constant rate in vacuum and compressive loa ding in the pressing direction on the electrical resistance of fiber c ompacts was investigated. Considerable decrease in electrical resistan ce occurred at 200-400 degrees C. The significant effect of small comp ressive deformations on the electrical resistance of fiber compacts, a nd the absence of such in powder compacts, as well as a hysteresis in resistance occurring upon loading and unloading the fiber compacts, is explained by the nature of interparticle bonds. These are rigid in th e powder compacts, and flexible-rigid in the fiber compacts.