In situ study on microwave sintering of ZTA ceramic: Effect of ZrO 2 content on densification, hardness, and toughness
Résumé
Better understanding of the effect of multimode-microwave sintering of zirconia-toughened alumina (ZTA) was investigated. A comparative dilatometric analysiswas conducted between conventional and microwave heating processes, to clarifythe influence of zirconia on the densification of ZTA under electromagneticfield.The thermal gradient on sample measurements indicates the change to the micro-wave volumetric heating is improved by zirconia which adsorbs microwaveenergy better, thus acting as a susceptor. The most beneficial effect on microstruc-ture, toughness, and hardness were observed at the optimal zirconia content of 10vol%. The results with both microwave and conventional sintering illustrate thestrengthening effect on the composite by zirconia. Of special interest, multimodemicrowave sintering creates afiner homogeneous microstructure, with resultinghardness and toughening comparable to those obtained for conventional sintering,as well as improved densification, and at lower cost.