A process control method for the electric current-activated/assisted sintering system based on the container-consumed power and temperature estimation

Abstract

In this paper, the current, voltage and temperature of the container of an electric current-activated/assisted sintering (ECAS) system are measured and recorded with respect to time during the sintering process. By post-processing of the recorded data, the power and thermal energy of the system container are calculated. Interpretation of the measured and post-processed data has provided a criterion: It has been found that the dissipated electrical power in quasi-steady state is almost equal to the power conducted from the container to the copper bars throughout the stiffs and the convection and radiation powers are negligible compared to the conducted power. Therefore, the container-stored thermal energy or the container surface temperature can be estimated from the dissipated electrical power with the values of the container heat capacitance and the stiff thermal resistances without the need for a temperature measurement equipment. If the thermal energy or the temperature required to make the samples has a known/required minimum value and if this amount of the thermal energy is provided to the sample, the sample production process can be stopped. In this study, for an actual implemented design, we suggest that ECAS current and voltages should be continuously measured in real time and the process is automatically terminated when the calculated steady-state container temperature becomes equal to the required container temperature. Therefore, a standard procedure for material production in ECAS system is provided to automate sample production and the performance of the produced samples is guaranteed.