Fracture Toughness of Yttria-Stabilized Cubic Zirconia (8Y-CSZ) Doped with Pure Silica

Abstract

In yttria-stabilized cubic zirconia, the addition of 0.15-5 mass% pure silica introduces a glass phase dispersing uniformly along grainboundary facets and at multiple junctions. For a grain size of 0.75 or 1.7 mm, the dispersion of the glass phase decreases the elastic modulus, the Vickers hardness and the elastic modulus-to-hardness ratio, whereas it affects little in the value of fracture toughness measured by an indentation method. The latter result arises because the decrease in the elastic modulus-to-hardness ratio is compensated by a decrease in the crack length for a given indentation load. Inspection of crack-propagation paths indicates that the glass phase with sizes smaller than those of the matrix grains is not a site for easy crack-propagation, but provides a site for a crack-deflection mechanism.

Effect of Initial Grain Size on Crack Healing Behavior under DC Electric Field of Zirconia (8Y‐CSZ) Ceramic

“…The H V and K IC values take almost the same values of 14.8 ± 1.2 GPa and 3.19 ± 0.20 MPa within experimental error, respectively, irrespective of both P and . These mechanical properties obtained in the fine, small, and coarse‐grained 8Y‐CSZs fit well with the reported data on 11.7–15 GPa and 1.3–2.2 MPa, [ 43,45–47 ] suggesting that the samples used in this study are similar to the conventional 8Y‐CSZs widely used in the previous studies, and the residual strain conditions formed by the Vickers indentation tests would also be almost constant irrespective of .…”

“…, [43,[45][46][47] suggesting that the samples used in this study are similar to the conventional 8Y-CSZs widely used in the previous studies, and the residual strain conditions formed by the Vickers indentation tests would also be almost constant irrespective of d 0 .…”

“…The Vickers hardness H V and the indentation fracture toughness K IC were calculated using the following equations. [ 42 ] andwhere a ave is the average length of the diagonal dimensions of a 1 and a 2 formed by the Vickers indenter, E is the Young's modulus of 218 GPa, [ 43 ] and c ave is the average half length of the crack measured from the center of the indent (Figure 2b).…”

“…where a ave is the average length of the diagonal dimensions of a 1 and a 2 formed by the Vickers indenter, E is the Young's modulus of 218 GPa, [43] and c ave is the average half length of the crack measured from the center of the indent (Figure 2b). .…”

Effect of DC and AC electric fields on crack healing behavior in 8 mol% yttria‐stabilized cubic zirconia polycrystal

“…The Vickers hardness H V and the indentation fracture toughness K IC were calculated by the following equations 44 : $$$$\begin{equation}{H_{\mathrm{V}}} = 0.1891 \times P{\mathrm{/}}{a_{{\mathrm{ave}}}}^2\left[ {{\mathrm{GPa}}} \right]\end{equation}$$$$and $$$$\begin{equation}{K_{{\mathrm{IC}}}} = 0.016 \times {\left( {E/{H_{\mathrm{V}}}} \right)^{1/2}} \times P/{c_{{\mathrm{ave}}}}^{3/2}[{\mathrm{MPa}} \sqrt{m}],\end{equation}$$$$where a ave is the average diagonal length of the indent, a 1 and a 2 are formed by the Vickers intender, E is Young's modulus of 218 GPa, 45 and c ave is the average half length of the crack measured from the center of the indent.…”