Affiliation:
1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan China
2. Hubei Longzhong Laboratory Wuhan University of Technology Xiangyang Demonstration Zone Xiangyang China
3. Department of Materials Loughborough University Loughborough UK
Abstract
AbstractPrestress strategy is effective to inhibit crack advancement and toughen structural materials such as concrete and glass. However, it is difficult to be utilized in ceramic because of the solid‐state processing. In this work, nanocrystalline alumina ceramic with high compressive prestress and coherently aligned nanograins were successfully prepared by the ultra‐high pressure sintering technology. The as‐prepared ceramics exhibited remarkably enhanced mechanical properties, including hardness of 25.9 GPa and fracture toughness of 3.2 MPa·m1/2, which were respectively 36% and 51% higher than corresponding parameters of sapphire. Ultra‐high pressure generated compressive prestress as large as several hundred megapascal, and coherent nanograins in the dimensions of 10–15 nm, which markedly contributed to the simultaneously enhancement in toughness and hardness for ceramic materials. The prestressing strategy provides a new opportunity for fabricating advanced ceramics with high failure resistance.
Funder
National Natural Science Foundation of China
Subject
Materials Chemistry,Ceramics and Composites