Analysis of the Power Density at the Onset of Flash Sintering. Issue 10 (14th June 2016)

• Record Type: Journal Article
• Authors: Raj, Rishi
• Editors: Chan, H.
• Is Part Of: Journal of the American Ceramic Society. Volume 99:Issue 10(2016)
• Page Start: 3226
• Page End: 3232
• Publication Date: 2016-06-14
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.14178
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract : The large bank of data for ceramics from experiments in flash sintering reveal a surprising characteristic: that the transition to a highly nonlinear rise in electrical conductivity—a signature event for the onset of the flash—occurs within a narrow range of power density. This condition holds for ceramics that are semiconductors, ionic conductors, electronic conductors, and insulators.They flash at temperatures that range from 300°C to 1300°C, and at electric fields from 10 V/cm to over 1000 V/cm. Yet, the power expenditure at the transition for all of them still falls within this narrow range. This, rather uniform value of power dissipation suggests that Joule heating is a key factor in instigating the flash. A general formulation is developed to test if indeed Joule heating alone can lead to the progression of such nonlinear behavior. It is concluded that Joule heating is a necessary but not a sufficient condition for flash sintering.