Effects of nano-ZrO2 content on microstructure and mechanical properties of GNPs/nano-ZrO2 reinforced Al2O3/Ti(C, N) composite ceramics. Issue 4 (April 2020)

• Record Type: Journal Article
• Authors: Cui, Enzhao; Zhao, Jun; Wang, Xuchao
• Is Part Of: Journal of the European Ceramic Society. Volume 40:Issue 4(2020)
• Page Start: 1532
• Page End: 1538
• Publication Date: 2020-04
• Subjects: Composite ceramics -- GNPs/nano-ZrO2 -- Mechanical properties -- Toughening mechanisms; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2019.11.039
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Dense Al2 O3 /Ti(C, N) composite ceramics reinforced with GNPs/nano-ZrO2 were fabricated by hot-press sintering. The effects of nano-ZrO2 content on the microstructure and mechanical properties of the prepared Al2 O3 /Ti(C, N)/GNPs/ZrO2 composites were investigated. Results showed that nano-ZrO2 inclusions refined the matrix grains significantly and resulted in the formation of intra-granular structure. Excellent comprehensive mechanical properties were achieved via addition of combined GNPs and nano-ZrO2 . In particular, the fracture toughness of composites incorporating GNPs (0.4 wt%)/ZrO2 (1 wt%) exceeded 11 MPa m 1/2, which was increased by more than 86 % compared with that of Al2 O3 /Ti(C, N) ceramic composites without GNPs/ZrO2 . The main toughening mechanisms have been identified as stress-induced phase transformation, crack bridging, deflection and pull-out of GNPs. The toughening effects originated from GNPs were enhanced with the introduction of nano-ZrO2 because of not only the residual stress resulted from phase transformation but also the formation of intra-granular structure with uneven surface around GNPs.