Influence of Porosity and Pore Distributions on Strength Properties of Porous Alumina

Effects of porosity and pore distribution on static strength properties of porous zirconia

“…As observed in Figure A, the crack appears to start from a particular point, which is located at the bottom right corner in this case. This is a typical fracture pattern observed in dense ceramic materials . For the porous specimens, it is challenging to distinguish the fracture origin based on these images only.…”

“…Hence, flaws are assumed to be in the form of inherent cracks. To determine the size distribution of ZR‐00, first of all, scale parameter is calculated to be 9.75 μm at porosity 0.64%, by extrapolating the trend of scale parameter a S with respect to porosity p , guided by the following equation: Location parameter is assumed to be 1 μm by referring to the values used in case of dense ceramics in previous researches . Then, the values for shape parameter, maximum crack size, and crack density were selected by using Monte Carlo simulation, which is explained in Section , such that the range of simulated strength is comparable with that of the experimental strength.…”

“…In order to determine the influence of pore distribution on the material's strength characteristics, a fracture mechanics procedure was proposed to estimate the strength of porous ceramics where pore distribution is considered to be equivalent to crack distribution. This was expanded from the earlier concept of fracture mechanics for estimating strength of dense ceramic materials, where inherent flaw, detected as fracture origin, is treated as crack . In the expanded concept for porous ceramics, pores were considered to be surrounded by virtual crack through which crack propagates.…”

“…The proposed procedure assumes that the behavior of pore distribution in porous ceramics is equivalent to that of crack distribution. Also, each pore is assumed to be surrounded by a virtual crack through which the crack propagates.…”

“…Hence, stress intensity factor for each virtual crack is estimated, and when the maximum stress intensity factor equals the critical stress intensity factor, fracture occurs . Based on the aforementioned principle, Monte Carlo simulations are carried out on 100 samples for each porosity level to estimate strength of the material. Finally, the statistical distribution is assessed through Weibull cumulative distribution function.…”