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Neutron Diffraction Measurements of the Residual Stresses in Al 2 O 3 ‐ZrO 2 (CeO 2 ) Ceramic Composites
Author(s) -
Wang XunLi,
Hubbard Camden R.,
Alexander Kathleen B.,
Becher Paul F.,
FernandezBaca Jaime A.,
Spooner Steve
Publication year - 1994
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.1151-2916.1994.tb09758.x
Subject(s) - materials science , neutron diffraction , diffraction , tetragonal crystal system , ceramic , rietveld refinement , composite material , residual stress , anisotropy , x ray crystallography , thermal expansion , lattice constant , composite number , analytical chemistry (journal) , mineralogy , crystallography , crystal structure , optics , chemistry , physics , chromatography
High‐resolution neutron powder diffraction was used to study the residual stresses in Al 2 O 3 ‐ZrO 2 (12 mol% CeO 2 ) ceramic composites containing 10, 20, and 40 vol% ZrO 2 (CeO 2 ). The diffraction data were analyzed using the Rietveld structure refinement technique. The analysis shows that for all samples, the CeO 2 ‐stabilized tetragonal ZrO 2 particles are in tension and the Al 2 O 3 matrix is in compression. For both the ZrO 2 particles and the Al 2 O 3 matrix, the average lattice strains are anisotropic and increase approximately linearly with a decrease in the corresponding phase content. It is shown that these features can be qualitatively understood by taking into consideration the thermal expansion mismatch between the ZrO 2 and Al 2 O 3 grains. Also, for all composite samples, the diffraction peaks are broader than the instrumental resolution, indicating that the strains in these samples are inhomogeneous. From an analysis of the refined peak shape parameters, the average root‐meansquare strain, which describes the distribution of the inhomogeneous strain field, was determined. Finally, the average residual stresses were evaluated from the experimentally determined average lattice strains and compared with recent results of X‐ray measurements on similar composites.