Phase transitions and transient liquid-phase sintering in calcium-substituted lanthanum chromite

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1997.tb03095.x· OSTI ID:532943

Chick, L A; Liu, J; Stevenson, J W; Armstrong, T R; McCready, D E; Maupin, G D; Coffey, G W; Coyle, C A ^[1]

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1. Pacific Northwest National Lab., Richland, WA (United States). Materials and Chemical Sciences Dept.

This paper investigates sintering and phase transitions of La{sub 0.7}Ca{sub x}CrO{sub 3} (0.25 {le} x {le} 0.35), a material useful as electrical interconnections in solid oxide fuel cells. Heating of the quenched, metastable single-phase chromite resulted in exsolution of CaCrO{sub 4} due to Ca solubility limitations below 1,200 C. A transient liquid phase formed between 850 and 1,000 C as the CaCrO{sub 4} melted, causing partial densification in materials having 0.25 < x < 0.30. A slight increase in Ca content induced an additional liquid-phase sintering event, likely due to melting of Ca{sub 3}(CrO{sub 4}){sub 2}, which facilitated near-complete densification by 1,250 C. After enhancing sintering, the secondary phases redissolved into the chromite.

• Sponsoring Organization: USDOE Morgantown Energy Technology Center, WV (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 532943
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 8 Vol. 80; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BULK DENSITY
CALCIUM OXIDES
CHEMICAL COMPOSITION
CHROMIUM OXIDES
LANTHANUM OXIDES
LIQUIDS
PHASE STUDIES
SINTERING
SOLUBILITY
TEMPERATURE RANGE 1000-4000 K