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Role of CeAl 11 O 18 in reinforcing Al 2 O 3 /Ti composites by adding CeO 2
Author(s) -
Shi Shengfang,
Cho Sunghun,
Goto Tomoyo,
Sekino Tohru
Publication year - 2020
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13629
Subject(s) - materials science , fracture toughness , toughening , composite material , microstructure , composite number , flexural strength , phase (matter) , rietveld refinement , toughness , strengthening mechanisms of materials , bridging (networking) , crystal structure , crystallography , computer network , chemistry , organic chemistry , computer science
This work discusses the reinforcement effect of elongated CeAl 11 O 18 phase on multifunctional Al 2 O 3 /Ti composites by adding CeO 2 to inhibit interfacial reaction and strengthen interface for inducing optimized performances. For this purpose, Al 2 O 3 /Ti composite with different contents of CeO 2 was fabricated and the microstructure, mechanical and electrical properties were studied. Results indicated that after CeO 2 was added, elongated CeAl 11 O 18 phase was formed within these composites. Owing to inhibited interfacial reaction between Al 2 O 3 and Ti, Ti content was increased and compositions of composites were calculated using Rietveld method based on X‐ray diffraction patterns. Attributed to the strengthening and toughening effects of CeAl 11 O 18 phase, 2 mol% CeO 2 added composite showed the highest flexural strength and fracture toughness of 576 MPa and 5.15 MPa·m 1/2 , which increased by 21% and 20% compared to Al 2 O 3 /Ti composite without CeO 2 addition. In this case, crack bridging by both Ti and CeAl 11 O 18 particles was the major toughening mechanism and the additional fracture toughness caused by CeAl 11 O 18 toughening effect reached a maximum. The role (crack bridging or particle pull‐out mechanism) of CeAl 11 O 18 in toughening Al 2 O 3 /Ti composites depended on the aspect ratio of these elongated particles, which was directly related to CeO 2 content. Because of the inhibition of interfacial reaction and the increase in Ti content, excellent electrical resistivity of composites after CeO 2 addition was maintained in spite of the formation of insulated CeAl 11 O 18 phase. All samples showed relatively low electrical resistivity of ~10 −3 Ωcm.