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Indexed by:期刊论文

Date of Publication:2018-11-01

Journal:JOURNAL OF THE AMERICAN CERAMIC SOCIETY

Included Journals:SCIE

Volume:101

Issue:11

Page Number:5151-5156

ISSN No.:0002-7820

Key Words:Al2O3; ZrO2; intragranular microstructure; mechanical property; nanocomposite; Si2N2O; Si3N4

Abstract:The formation of intragranular microstructure in Al2O3/ZrO2 and Si2N2O/Si3N4 nanocomposites was analyzed, and the effect of intragranular microstructure on the mechanical properties of nanocomposites was investigated. Results suggest 3 requisite conditions for the formation of intragranular microstructure and the role of intracrystalline glass phase and scar microstructure. In case of Al2O3/ZrO2, the intragranular microstructure leads to the formation of transgranular fracture, which in turn improves the mechanical properties via strengthening and toughening. On the other hand, in case of Si3N4/Si2N2O nanocomposites, intragranular microstructure reduces the possibility of bridging, pulling out, and crack deflection, thereby leading to the deterioration of strength and toughness. Based on these results, we can conclude that the formation of intragranular microstructure does not necessarily improve the mechanical properties in all kinds of materials. Rather, the effect of intragranular microstructure on the mechanical properties of nanocomposites is related to the strengthening and toughing mechanism of matrix materials.