Microwave versus conventional sintering: Estimate of the apparent activation energy for densification of alpha-alumina and zinc oxide

Fei Zuo (1, 2, 3) , Alexandre Badev (4) , Sébastien Saunier (1, 2, 3) , Dominique Goeuriot (1, 2, 3) , Romain Heuguet (4) , Sylvain Marinel (4)

1 MPE-ENSMSE - Département Mécanique et Procédés d'Elaboration
2 SMS-ENSMSE - Centre Science des Matériaux et des Structures
3 LGF-ENSMSE - Laboratoire Georges Friedel
4 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

A comparative study between the conventional and 2.45 GHz microwave multimode sintering behavior of insulator (alpha-Al2O3) and semi-conductive ceramic (ZnO) was systematically investigated. The apparent activation energy of nonisothermal sintering was determined by way of the Arrhenius plot of densification data at constant heating rates (CHR) and the concepts of Master Sintering Curves (MSCs), respectively. During microwave densification process, the apparent activation energy was about 90 kJ/mol less than the value for conventional sintering of Al2O3 applying these two estimation methods. However, an opposite result was obtained in the case of ZnO, although its densification process had been also accelerated by microwave as well as Al2O3. The significant differences in activation energy give a good proof of the difference in diffusion mechanism induced by the electromagnetic field underlying microwave sintering.

Mots clés: Alpha-Al2O3; Activation energy; Sintering; Microwave processing

Domaines: Matériaux

Fei Zuo, Alexandre Badev, Sébastien Saunier, Dominique Goeuriot, Romain Heuguet, et al.. Microwave versus conventional sintering: Estimate of the apparent activation energy for densification of alpha-alumina and zinc oxide. Journal of the European Ceramic Society, 2014, 34 (12), pp.3103-3110. ⟨10.1016/j.jeurceramsoc.2014.04.006⟩. ⟨emse-01063729⟩