Microwave sintering process model.

In order to simulate and optimize the microwave sintering of a silicon nitride and tungsten carbide/cobalt too/bits process, a microwave sintering process model has been built. A cylindrical sintering furnace was used containing a heat insulating layer, a susceptor layer, and an alumina tube containing the green toolbit parts between parallel, electrically conductive, graphite plates. Dielectric and absorption properties of the silicon nitride green parts, the tungsten carbide/cobalt green parts, and an oxidizable susveptor material were measured using perturbation and waveg Hide transmission methods. Microwave absorption data Were measured over a temperature range from 20°C to 800°C. These data were then used in the microwave process model which assumed plane wave propagation along the radial direction and included the microwave reflection at each interlace between the materials and the microwave absorption in the bulk materials. Heal transfer between the components inside the cylindrical sintering furna...