کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7208029 | 1469085 | 2016 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Spatial distribution of residual stresses in glass-ZrO2 sphero-cylindrical bilayers
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
سایر رشته های مهندسی
مهندسی پزشکی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Spatial distribution of residual stresses in glass-ZrO2 sphero-cylindrical bilayers Spatial distribution of residual stresses in glass-ZrO2 sphero-cylindrical bilayers](/preview/png/7208029.png)
چکیده انگلیسی
Residual stresses arising from inhomogeneous cooling after sintering have shown to play a preponderant role in the higher incidence of chippings observed for glass-zirconia dental prostheses. Still, current descriptions of their nature and distribution have failed to reconcile with clinical findings. Therefore, an axisymmetric sphero-cylindrical bilayer model was used in this study to determine the effect of the cooling rate on the final spatial distribution of residual stresses. Zirconia frameworks with two different radii (1.6 and 3.2 mm) were CAD/CAM fabricated. Subsequent glass overlays with two different thickness ratios (1:1 and 2:1) were generated and heat pressed onto the zirconia substrates. The obtained structures were submitted to a last firing process and fast- (45 °C/s) or slow-cooled (0.5 °C/s) to room temperature. Unbonded bilayers were produced by firing glass overlays onto boron nitride coated zirconia. Thin sagittal and transversal sections were obtained from the specimens to assess residual stress distribution by means of light birefringence. The applied cooling rates did not affect distribution or magnitude of radial residual stresses (sagittal sections), whereas increased hoop stress magnitudes were measured (transversal sections) in fast-cooled specimens. A distinct stress nature was observed for the hoop stress component of unbonded overlays after fast cooling. Interaction between stress components seems to govern the final stress distribution, highlighting the importance of a multiaxial assessment of this problem in three-dimensional structures.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the Mechanical Behavior of Biomedical Materials - Volume 60, July 2016, Pages 535-546
Journal: Journal of the Mechanical Behavior of Biomedical Materials - Volume 60, July 2016, Pages 535-546
نویسندگان
Michael Wendler, Renan Belli, Anselm Petschelt, Ulrich Lohbauer,