Premium
Thermal Conductivity and Thermal Expansion Coefficients of the Lanthanum Rare‐Earth‐Element Zirconate System
Author(s) -
Lehmann Henry,
Pitzer Dieter,
Pracht Gerhard,
Vassen Robert,
Stöver Detlef
Publication year - 2003
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2003.tb03473.x
Subject(s) - lanthanum , thermal expansion , thermal conductivity , pyrochlore , zirconate , materials science , thermal barrier coating , cubic zirconia , yttria stabilized zirconia , mineralogy , analytical chemistry (journal) , inorganic chemistry , composite material , chemistry , coating , ceramic , organic chemistry , titanate , phase (matter)
To enhance the insulating properties of a thermal barrier coating, one has to focus on new materials with lower intrinsic thermal conductivity than established yttria‐stabilized zirconia. Substances with pyrochlore structure were investigated. Starting from lanthanum zirconate, substitutions of the lanthanum by other trivalent rare‐earth elements were made, and the thermal conductivity and the thermal expansion coefficient of the manufactured materials were measured. A complete substitution of the lanthanum led to increased thermal expansion coefficients, whereas the partial substitution did not show an appreciable effect. The thermal conductivities of the modified materials were lower than that of the pure lanthanum zirconate for temperatures <1000°C for all amounts and elements of substitution. A comparison of the observed values with calculated values of the thermal conductivities showed a relatively good agreement.