Effect of Nb[sub 2]O[sub 5] alloying on thermal expansion anisotropy of 2 mol% Y[sub 2]O[sub 3]-stabilized tetragonal ZrO[sub 2]

Journal Article · Mon Nov 01 00:00:00 EST 1993 · Journal of the American Ceramic Society; (United States)

OSTI ID:5727508

Kim, Daejoon ^[1]; Becher, P F; Hubbard, C R ^[2]

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1. Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Ceramics Div.
2. Oak Ridge National Lab., TN (United States)

Tetragonal ZrO[sub 2] (t-ZrO[sub 2]) solid solutions were prepared with additions of 2 mol% Y[sub 2]O[sub 3] plus up to 0.45 mol% Nb[sub 2]O[sub 5]. The thermal expansion coefficients in both the a- and c-axis lattice directions increased with Nb[sub 2]O[sub 5] alloying and the thermal expansion in the c-axis direction was greater than that in the a-axis direction over the entire composition range. This anisotropic thermal expansion behavior was related to the 4-fold coordination of Nb[sup 5+] with oxygen ions in t-ZrO[sub 2] solid solutions in the system ZrO[sub 2]-Y[sub 2]O[sub 3]-Nb[sub 2]O[sub 5]. The fracture toughness continuously increased with Nb[sub 2]O[sub 5] alloying and suggested that the c/a axial ratio is a more significant factor than the internal stress that arises from the thermal expansion anisotropy, in the determination of the transformability of t-ZrO[sub 2] in this system.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5727508
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 76:11; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NIOBIUM OXIDES
FABRICATION
THERMAL EXPANSION
YTTRIUM OXIDES
ZIRCONIUM OXIDES
ANISOTROPY
CHALCOGENIDES
EXPANSION
NIOBIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
ZIRCONIUM COMPOUNDS
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Cermets
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