Effect of sintering parameters and composition on the resistivity of a cermet used as an electrical feedthrough

The improvement of the electrical characteristics of an alumina/molybdenum cermet presently used as an electrical feedthrough was demonstrated. Samples of 50 wt % alumina/50 wt % molybdenum cermets were fabricated using 99% Al2O3 94% Al2O3 and 91% Al2O3. Sintering was performed at 1400 C, 1500 C, or 1600 C using three different hydrogen dew points (-45 C, -10 C, +25 C). After sintering, the resistivity of the cermet samples was measured by using a four-point probe technique. The results show that the resistivity of the cermet decreased significantly as the purity of the alumina used in the cermet decreased from 99% to 91% alumina.