Grain size dependent residual microstresses in submicron A12O3 and ZrO2

Wet Erosive Wear of Alumina Densified with Magnesium Silicate Additions

“…The average residual stresses determined by photoluminescence spectroscopy in the pure alumina examined here are less than those reported by Ma and Clarke 13 (Ͼ200 MPa for an alumina with a grain size of 16 m) but are closer to those reported by Krell et al 27 of 60 MPa for 7 m grain-sized alumina. In the present work, the standard deviation in local stress measured from the luminescence peak width is much greater than the mean residual stress deduced from the peak shift, which suggests that the high fluctuating local stresses in the magnesium silicate-densified aluminas are not caused by thermal contraction anisotropy of the alumina grains but by thermal expansion mismatch between the alumina and localized pockets of amorphous intergranular silicate and the secondary crystalline aluminosilicate phases.…”

Vibrational Properties of Zr(Hf)B2–SiC UHTC Composites by Micro-Raman Spectroscopy

“…The processing-induced intergranular microstresses develop during the cooling of multiphase composite whenever materials with different coefficients of thermal expansion (CTE) and elastic moduli are bonded together [37][38][39] where as the intragranular residual microstresses result in anisotropic single phase polycrystalline material due to thermal contraction differences between the crystallites [40][41][42]. Mechanical deformation-induced microstresses develop due to elastic-plastic deformation within the material or due to strain incompatibility within the grains.…”

Improved sliding wear-resistance of alumina with sub-micron grain size: A comparison with coarser grained material

“…[23][24][25] Following the proposition of Krell et al 26 Table 2. However, in the second set of data, the values of σ D increase towards finer microstructures in a comparatively moderate fashion.…”