Nanocrystalline powders were used to prepare fracture test specimens of2Y-TZP with average grain sizes between 150 and 900 nm. Crack extension and attendant R-curve behaviour were studied in both air and vacuum. The plateau values in air and vacuum increase linearly with grain size from 3.1 to 5.1MPam1/2 and from 4.7 to 6.7MPam1/2, respectively. The size of the process zonewas quantified using Raman microscopy and the results correlated to both the plateau values and the shape of the R-curve as a function of grain size.
Smirnov, N. N., & smirnov, N. N. (1964). On the quantity of allochthonous pollen and spores received by the Rybinsk Reservoir. Hydrobiologia, 24(1–2), 421–429. https://doi.org/10.1007/BF00170413