Elastic Constants of Synthetic Single‐Crystal Corundum at Room Temperature

Wachtman, J. B.; Tefft, Wayne E.; Lam, D. G.; Stinchfield, R. P.

doi:10.1111/j.1151-2916.1960.tb13663.x

Cited by 26 publications

(11 citation statements)

References 3 publications

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“…The coefficients of thermal expansion (CTEs) used for ␣-alumina in the analysis were as follows: ␣ 11 ϭ 8.6 ϫ 10 Ϫ6 /°C and ␣ 33 ϭ 9.3 ϫ 10 Ϫ6 /°C. 11 Based on this data, a finite-element grid with associated properties is generated on which mechanical and/or thermal loading can be applied. Then, a solution is obtained for the specified boundary conditions, distortion, and temperature change.…”

Section: (1) Object-oriented Finite-element Analysismentioning

confidence: 99%

Residual‐Stress Predictions in Polycrystalline Alumina

Vedula¹,

Glass²,

Saylor³

et al. 2001

Journal of the American Ceramic Society

118

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Microstructure-level residual stresses occur in polycrystalline ceramics during processing, as a result of thermal expansion anisotropy and crystallographic misorientation across the grain boundaries. Depending on the grain size, the magnitude of these stresses can be sufficiently high to cause spontaneous microcracking when cooled from the processing temperature. They are also likely to affect where cracks initiate and propagate under macroscopic loading. The magnitudes of residual stresses in untextured and textured alumina samples have been predicted using experimentally determined grain orientations and object-oriented finite-element analysis. The crystallographic orientations have been obtained using electron-backscattered diffraction. The residual stresses are lower and the stress distributions are narrower in the textured samples, in comparison with those in the untextured samples. Crack initiation and propagation also have been simulated, using a Griffith-like fracture criterion. The grain-boundaryenergy:surface-energy ratios required for computations are estimated using atomic-force-microscopy thermal-groove measurements.

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Section: (1) Object-oriented Finite-element Analysismentioning

confidence: 99%

Residual‐Stress Predictions in Polycrystalline Alumina

Vedula¹,

Glass²,

Saylor³

et al. 2001

Journal of the American Ceramic Society

118

View full text Add to dashboard Cite

show abstract

“…The effect of the mild elastic anisotropy of ruby on the stress field was assessed using the analysis of Sih et al 10 . Using the sapphire elastic constants of Wachtman et al 11 , it was found that the hydrostatic stress component predicted was within 8% of the elastically isotropic solution for all points, and within 4% for points ahead of the crack tip (i.e. absolute value of the polar angle θ, defined below, <90 • ).…”

Section: Comparison Of Results With Theoretical Crack Tip Stress Fieldmentioning

confidence: 99%

Piezospectroscopic measurement of the stress field around an indentation crack tip in ruby using SEM cathodoluminescence

Todd

Stowe

Galloway³

et al. 2008

Journal of the European Ceramic Society

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“…FEM calculations of stress distribution were performed using the software ANSYS ver.5.7 (ANSYS, Inc., Canonsburg, PA). For the stiffness C ij values, 19 and [ D ] matrix values of anisotropic stiffness d ij for sapphire, the reported values were used 19,20 in the present calculations. In these calculations, three‐dimensional solid models were used, and c‐ or a‐ plane was set on the XY plane where a load was applied to the Z direction.…”

Section: Methodsmentioning

confidence: 99%

Lattice Strain and Dislocations in Polished Surfaces on Sapphire

Saito

Hirayama

Yamamoto

et al. 2005

Journal of the American Ceramic Society

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Polishing of ceramics, surface defects and strain are introduced that influence the mechanical properties in the final products. In this study, the sapphire surfaces with a‐plane and c‐plane were polished using several kinds of diamond slurry, and the introduced damaged zones were investigated using transmission electron microscopy (TEM), high‐resolution TEM, and TEM‐CBED (convergent beam electron diffraction). It was found that the types of slip systems and strain distribution were different between the a‐plane‐polished and the c‐plane‐polished specimens. That is, the basal slip and the prism slip were mainly activated in the c‐ and a‐plane‐polished specimens to form the different damaged zones. This difference was probably due to the difference in the direction and angle from the slip plane and applied shear stress during the polishing. On the basis of these observations, the types of introduced dislocations and distribution of strain were discussed to clarify the mechanism of polishing.

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Elastic Constants of Synthetic Single‐Crystal Corundum at Room Temperature

Cited by 26 publications

References 3 publications

Residual‐Stress Predictions in Polycrystalline Alumina

Residual‐Stress Predictions in Polycrystalline Alumina

Piezospectroscopic measurement of the stress field around an indentation crack tip in ruby using SEM cathodoluminescence

Lattice Strain and Dislocations in Polished Surfaces on Sapphire

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