Control of zirconia surface phases in annealed alumina with Y/sup +//Zr/sup +/ implantation ratios

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Journal of Materials Engineering; (USA)

DOI:https://doi.org/10.1007/BF02834462· OSTI ID:5123985

Cochran, J K; Pope, S G ^[1]; Legg, K O; SolnickLegg, H F ^[2]

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1. Georgia Inst. of Tech., Atlanta, GA (USA). School of Material Engineering
2. Ionic Atlanta, Inc., Atlanta, GA (US)

The authors discuss an effort to transformation toughen alumina surfaces, in which Y/sup +/ was implanted in sapphire previously implanted with Zr/sup +/ at a dose of 1.25 x 10/sup 17/ ions/cm/sup 2/. The Y/sup +/ implant doses ranged from 1 to 10 x 10/sup 15/ ions/cm/sup 2/ and the double implants were labelled Y/sup +//Zr/sup +//Al/sub 2/O/sub 3/. Annealing in the air at 1400{sup 0}C produced a uniform surface film of polycrystalline ZrO/sub 2/ doped with Y/sub 2/O/sub 3/ which had a grain size of 0.1 to 1.0 {mu}m. From x-ray diffraction (XRD), the ZrO/sub 2/ phases transitioned from monoclinic to tetragonal to cubic as the Y/sub 2/O/sub 3/ content increased from 0 to 4 m/o based ion zirconia content. Obtaining only cubic zirconia was surprising, because pure cubic ZrO/sub 2/ should result only above 9.2 m/o Y/sub 2/O/sub 3/. The ratios of Y to Zr measured by electron spectroscopy for chemical analysis (ESCA) depth profiling for the high dose Y/sup +/ implant was equivalent to 10 m/o Y/sub 2/O/sub 3/ in ZrO/sub 2/ rather than the implanted ratio of 4 m/o. The higher than expected Y concentrations agreed with the XRD results and were probably produced by Zr removal by ion milling during the high Zr/sup +/ dose implant. Surface fracture toughness, as measured by indentation, decreased as yttria content increased because elimination of monoclinic ZrO/sub 2/ from the precipitate phases prevented a surface compression layer created by the tetragonal to monoclinic ZrO/sub 2/ transition on cooling from annealing temperatures.

• OSTI ID: 5123985
• Journal Information: Journal of Materials Engineering; (USA), Journal Name: Journal of Materials Engineering; (USA) Vol. 11:2; ISSN JMAEE; ISSN 0931-7058
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
656003 -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ANNEALING
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL ANALYSIS
COHERENT SCATTERING
COOLING
CORUNDUM
CRYSTAL DOPING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
ELECTRON SPECTROSCOPY
GRAIN SIZE
HEAT TREATMENTS
ION IMPLANTATION
IONS
MICROSTRUCTURE
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
POLYCRYSTALS
SAPPHIRE
SCATTERING
SIZE
SPECTROSCOPY
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM IONS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM IONS
ZIRCONIUM OXIDES