Sintering of a quasi-crystalline powder using spark plasma sintering and hot-pressing

Sintering experiments on a granulated AlCuFeB quasi-crystalline powder were performed using hot-pressing (HP) and spark plasma sintering (SPS). By coupling the analysis of a sintering law (derived from creep rate equations) and comparative observations of almost fully dense sintered samples using mainly microprobe analysis and transmission electron microscopy, hypotheses about the densification mechanism(s) involved were expressed. Whatever sintering is performed by SPS or HP, it is proposed that two regimes exist, the difference between them lying in the fact that grain boundaries are/are not perfect sources/sinks of vacancies.