Grain Growth and Twin Formation in 0.74PMN·0.26PT

Autor:	Jong-Moo Huh, Carol A. Handwerker, Jay S. Wallace, John E. Blendell
Rok vydání:	2002
Předmět:	Equiaxed crystals education.field_of_study Materials science Population Metallurgy Nucleation food and beverages Sintering Titanate Grain growth Volume fraction Materials Chemistry Ceramics and Composites Composite material education Electron backscatter diffraction
Zdroj:	Journal of the American Ceramic Society. 85:1581-1584
ISSN:	1551-2916 0002-7820
DOI:	10.1111/j.1151-2916.2002.tb00315.x
Popis:	The mechanisms controlling normal and exaggerated grain growth in lead magnesium niobate–lead titanate (PMN–PT) ceramics have been investigated by varying the PbO-based liquid-phase volume fraction from 0.03 to 0.6 and sintering temperature from 900° to 1100°C. There is a transition in matrix grain growth rate and matrix grain shape with liquid fraction; samples with liquid volume fractions less than ∼0.15 show relatively small equiaxed grains resulting from grain-to-grain impingement. Samples with higher liquid fractions show significantly larger, facetted, cube-shaped grains, whose size is independent of liquid fraction, indicating that a surface nucleation rate mechanism controls growth in this regime. Exaggerated grains were found in the high liquid fraction samples. Electron backscatter diffraction showed that all of the exaggerated grains contained 60°〈111〉 twins but none of the normal matrix grains contained twins. The reentrant angles in the twinned grains give them a growth advantage over untwinned grains, resulting in a population of exaggerated grains.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::4e5dddf02e3ec51d006d5e15d6eabf07 https://doi.org/10.1111/j.1151-2916.2002.tb00315.x Zobrazit plný text záznamu