Zhipeng Xie

Title : Nanostructured zirconia-based ceramic material fabricated by an oscillatory pressure sintering process

Abstract:

The actual strength of ceramics is much lower than their theoretical value due to considerable flaws appearing during powder consolidation. A straightforward approach to improve their fracture strength is to minimize the quantity and size of flaws within ceramics. Here, we report a sintering strategy to consolidate ultrastrong ceramics by introducing oscillatory pressure. We have fabricated a fully dense ZrO₂ ceramics contained 3mol.% Y₂O₃, ZrO₂ ceramics strengthened by 20wt.% Al₂O₃ with a three-point bending strength of up to 1.81 GPa, 2.1 GPa, respectively,  which are the strongest zirconia-based ceramics yet achieved. Strengthening of the material is based on adopting a dynamic oscillatory pressure during sintering to remove various flaws (including agglomerated-pores and micro-pores), strengthen grain boundaries (mainly owing to the formation of a high number density of coherent grain boundaries structure). We believe that this sintering process can be applied to manufacture other ceramics with extremely high strength for structural applications.

Audience take away:

• we report a sintering strategy to consolidate ultrastrong ceramics by introducing oscillatory pressure. 
• Strengthening of the material is based on adopting a dynamic oscillatory pressure during sintering to remove various flaws and strengthen grain boundaries.
• We believe that this sintering process can be applied to manufacture other ceramics with extremely high strength for structural applications.

Biography:

Prof. ZhiPeng Xie studied material science at the Tsinghua University, Beijing and graduated as Ph.D in 1993. He then joined the research group of Prof. Yong Huang at School of Material Science and Engineering Tsinghua University. After one year postdoctoral fellowship at the Swiss Federal Institute of Technology in 1996, he obtained the position of an Associate Professor at the Tsinghua University followed by professorship in 2002. He also has been a visiting scholar at Monash University. His work over the past 25 years has spanned a broad range of nanostructured ceramics,  fabrication science & technologies and  200 papers have been published in recent years.