Lecture by Prof. Jean-Marc Chaix
The Priority Programme Coordination Team would like to invite you to the lecture by Prof. Jean-Marc Chaix (Univ. Grenoble Alpes, CNRS, Grenoble INP, SIMaP) on Tuesday, April 26th, 2022 at 2:00 pm. The title is: „Flash sintering: Managing electro-thermal instability to make it a process”. Please find the abstract of the lecture attached at the end.
The talk will be given as a hybrid-presentation (face-to-face and online). If you would like to hear the talk in the conference room (Forschungszentrum Jülich, building 01.3z, room 3001), please contact us (FieldsMatter - Contact) as seating is limited due to the Corona pandemic.
Please find enclosed the link to join the presentation online: https://bluejeans.com/386809920/9519.
We look forward seeing you.
Flash sintering of ceramics exploits a simple idea: apply an electric voltage (AC or DC) to a preheated compact of conductive ceramic, without mechanical load. If the initial temperature is high enough, and the voltage sufficient, after a waiting period, the electric current surges, the temperature rises violently and the sample densifies in a few seconds or a few minutes when a second step under constant current is applied. Unlike SPS, the technique requires no pressure, no matrix and no current artifice (pulses, etc.). This simplicity of implementation masks a set of coupled phenomena that make the technique as interesting as it is difficult to control. The first ones are the need to ensure charge transfer between the electrons in the circuit and the charge-carrying ions in the ceramic (electrode reactions) and the intrinsic electro-thermal instability that tends to amplify any defect of the material, thermal losses or power supply. The viscoplastic deformations associated with rapid densification during sintering may also contribute.
Based on experimental work and numerical simulations carried out by the Grenoble teams of the SIMaP and LEPMI laboratories and on data from the literature, the talk will examine some specificities and problems of flash sintering with a view to making this technique a manufacturing process for ceramics.