Mold design and temperature field analysis on electric current sintering of electrically conductive powders

In order to probe and improve temperature field during electric current sintering, high strength ceramic and graphite were used respectively as female die during sintering. Experiments and finite element method (FEM) were conducted to characterize the electric current density, resistance heating and temperature distribution in the specimen/die/punch. Obviously higher heating rate, higher final sintering temperature and higher gradient temperature were found in specimens when high strength ceramics was used as female die, compared with graphite female die under the conditions of the same die dimension and sintering parameters. A composite die was proposed to reduce and even eliminate the differences as well as to improve heating rate of the specimen. The experimental results are in good agreement with calculated values by FEM, which indicates that FEM may be an effective analysis method to simulate temperature field of electric current sintering.