Microwave Sintering Process Model

Abstract

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 furnace was also included in the model. The simulated heating process data for both silicon nitride and tungsten carbide/cobalt samples closely follow the experimental data. By varying the physical parameters of/lie sintering furnace model, such as the thickness of ihe susceptor layer, the thickness of the alumina tube wall, the sample load volume and the graphite plate mass, the model data predicts their effects which are helpful in optimizing those parameters in the industrial sintering process.

Key Words:

• Microwave sintering
• sintering process model
• microwave absorption modeling
• heat transfer
• silicon nitride
• tungsten carbide/cobalt
• oxidizable susceptor

Additional information

Notes on contributors

Hu Peng

Hu Pen, is presently with Long Tech Ltd. Co. Changsha, Hunan, P.R. China, W. R Tinga* is affiliated with the department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada, U. Sundararaj and R.L. Eadie are affiliated with the department of Chemical and Niaterials Engineering, University of Alberta.

W.R. Tinga

Hu Pen, is presently with Long Tech Ltd. Co. Changsha, Hunan, P.R. China, W. R Tinga* is affiliated with the department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada, U. Sundararaj and R.L. Eadie are affiliated with the department of Chemical and Niaterials Engineering, University of Alberta.

U. Sundararaj

Hu Pen, is presently with Long Tech Ltd. Co. Changsha, Hunan, P.R. China, W. R Tinga* is affiliated with the department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada, U. Sundararaj and R.L. Eadie are affiliated with the department of Chemical and Niaterials Engineering, University of Alberta.

R.L. Eadie

Hu Pen, is presently with Long Tech Ltd. Co. Changsha, Hunan, P.R. China, W. R Tinga* is affiliated with the department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada, U. Sundararaj and R.L. Eadie are affiliated with the department of Chemical and Niaterials Engineering, University of Alberta.