ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The residual thermoelastic stresses were studied in Al2O3–ZrO2 (monoclinic zirconia, m-ZrO2) and Al2O3–ZrO2(Y2O3) (tetragonal zirconia, t-ZrO2) fibrous eutectics that were produced via the laser floating zone method, using different piezospectrosocopic probes. The luminescence of the R-lines of ruby (Cr3+ in Al2O3 phase) was used to determine the stresses in the Al2O3 matrix, assuming that the stress state in the fibers was transversally isotropic. The sapphire matrix was subjected to tensile stresses in the Al2O3–m-ZrO2 eutectics. The hydrostatic stress component attained a value of 1.13 GPa in well-ordered regions. In contrast, sapphire was in compression in the Al2O3–ZrO2(Y2O3) fibers, and the hydrostatic stress was −0.37 GPa in both ordered and disordered regions. The influence of the microstructure in the residual stresses was explained through thermoelastic analyses, based on a self-consistent method. In addition, the Raman spectra of m-ZrO2 and the 417 cm−1 Raman mode of Al2O3 were measured in samples that showed different microstructures and thermoelastic stresses. An approximate linear dependence was observed in the tension–compression range between frequency shifts of the Al2O3R-lines and those of the 417 cm−1 Raman mode.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.2000.tb01626.x
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