Effects of pulsed current waveforms on sample temperature and sintering behavior in PECS of alumina

Abstract

Pure Al2O3 powder was sintered by a pulsed electric current sintering (PECS) process with different pulse current waveforms from two types of power generators: an inverter (frequency 16 kHz) type and a pulsed direct current (DC) (frequency 300Hz) type. The sample temperature during the PECS process as well as the sintering behavior was investigated. The effects of pulse current waveform on the sintering process were discussed. For the same die temperature ranging from 1100 to 1400 °C at holding period, the sample temperature under experiments using the inverter was higher than that under experiments using the pulsed DC. Densification and grain growth were predominated by sample temperature and did not depend on the pulse current waveform directly.