Formation, characterization, and hot isostatic pressing of Cr{sub 2}O{sub 3}-doped ZrO{sub 2} (0,3 mol% Y{sub 2}O{sub 3}) prepared by hydrazine method

Journal Article · Sun Dec 31 23:00:00 EST 1995 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1996.tb07895.x· OSTI ID:203548

Hirano, Shingo; Yoshinaka, Masaru; Hirota, Ken; Yamaguchi, Osamu ^[1]

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1. Doshisha Univ., Kyoto Tanabe (Japan)

In the ZrO{sub 2}-Cr{sub 2}O{sub 3} system, metastable t-ZrO{sub 2} solid solutions containing up to 11 mol% Cr{sub 2}O{sub 3} crystallize at low temperatures from amorphous materials prepared by the hydrazine method. The lattice parameter c decreases linearly from 0.5149 to 0.5077 nm with increased Cr{sub 2}O{sub 3} content, whereas the lattice parameter a is a constant value (a = 0.5077 nm) regardless of the starting composition. At higher temperatures, transformation (decomposition) of the solid solutions proceeds in the following way: t(ss) {yields} t(ss) + m + Cr{sub 2}O{sub 3} {yields} m + Cr{sub 2}O{sub 3}. Above 11 mol% Cr{sub 2}O{sub 3} addition, c-ZrO{sub 2} phases are formed in the presence of Cr{sub 2}O{sub 3}. The t-ZrO{sub 2} solid solution powders have been characterized for particle size, shape, and surface area. They consist of very fine particles (15--30 nm) showing thin platelike morphology. Dense ZrO{sub 2}(3Y)-Cr{sub 2}O{sub 3} composite ceramics ({approx} 99.7% of theoretical) with an average grain size of 0.3 {micro}m have been fabricated by hot isostatic pressing for 2 h at 1,400 C and 196 MPa. Their fracture toughness increases with increased Cr{sub 2}O{sub 3} content. The highest K{sub 1c} value of 9.5 MPa {center_dot} m{sup 1/2} is achieved in the composite ceramics containing 10 mol% Cr{sub 2}O{sub 3}.

• Sponsoring Organization: USDOE
• OSTI ID: 203548
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 1 Vol. 79; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
AQUEOUS SOLUTIONS
CHLORIDES
CHROMIUM OXIDES
CRYSTAL STRUCTURE
DOPED MATERIALS
FRACTURE PROPERTIES
HOT PRESSING
HYDROGEN GENERATORS
LATTICE PARAMETERS
MATERIALS
MHD GENERATORS
PARTICLE SIZE
SHAPE
SINTERING
SOLID SOLUTIONS
SURFACE AREA
SYNTHESIS
YTTRIUM OXIDES
ZIRCONIUM OXIDES