Sintering at extreme rates: A comparative study between blacklight and ultrafast high-temperature sintering

Abstract

Given the urgent need to address the climate and energy crisis, there is a growing emphasis on reducing energy consumption and time in ceramic sintering processes, which are pivotal in various industries. Innovative approaches, such as blacklight sintering (BLS) and ultrafast high-temperature sintering (UHS), are emerging as promising solutions due to their unprecedented heating rates and energy efficiency. This study delves into the potential applicability of BLS and UHS for the model material barium titanate (BaTiO₃), as compared with conventional sintering (CS). The highest density achieved with UHS (95%) was the same as in CS but with a much shorter heating time (90 s). Due to its effective UV light absorption, BLS yielded 90% densification for BaTiO₃ in only 30 s. The time- and temperature-dependent densification curves of BaTiO₃ shed light on comparative performance and kinetics in BLS, UHS, and CS. The main factor limiting the sintered density achieved under all conditions was pore/boundary separation and thus the relative rates of grain boundary and pore motion and densification. Furthermore, the study highlights the presence of a transient density gradient throughout the thickness of the sample during BLS. However, by the final stage, this density gradient becomes negligible.