Promoting the flash sintering of ZnO in reduced atmospheres to achieve nearly full densities at furnace temperatures of 120 degrees C

摘要

Using ZnO as a model system, a strong dependence of the onset flash sintering temperature on the atmosphere has been discovered. In the best cases, ZnO specimens have been sintered to >97% relative densities (with fine grain sizes of similar to 1 mu m) in similar to 30 s at furnace temperatures of <120 degrees C in Ar + 5 mol.% H-2. The enhanced conductivities of ZnO powder specimens in reduced atmospheres are responsible for the substantial decreases of the onset flash sintering temperatures. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.