Temperature, Current, and Heat Loss Distributions in Reduced Electrothermal Loss Spark Plasma Sintering

We present a method for spark plasma sintering (SPS) with reduced thermal and electrical losses compared to all-graphite SPS. Relative to the all-graphite configuration, the present design significantly reduces both the required power input and total current for the same synthesis temperature (e.g., 7.5 vs 0.6 kW and 1530 vs 350 A at 900 ^oC). These reductions allow for significantly smaller power source and process chamber, drastic reduction in energy consumption, easier thermal management, and enhanced synthesis/homogenization by eliminating die “leakage” currents, allowing for maximization of current density and its intrinsic effect on homogenization by diffusion. A finite element (FE) model solution for temperature and current distributions, as well as thermal losses for both the present and the all-graphite SPS setups, is presented and compared to experimental results.