Weibull analysis of ceramics under high stress gradients

Push-to-pull tensile testing of ultra-strong nanoscale ceramic–polymer composites made by additive manufacturing

“…6. Size dependent strengthening of alumina from the macro-to the nanoscale, theoretical model and experimental data [10,[22][23][24]27]. The strength to thickness relation is described by different scaling laws.…”

“…4. It is seen that the strength of ALD alumina is of the order of 3-5 GPa, which is 10 times higher than values for conventional bulk alumina, which are in the range of 250 MPa [10,23] to 600 MPa [10,24]. With decreasing coating thickness, the fracture strength of alumina strongly increases from 3.5 GPa at 100 nm to values of above 5 GPa for a thickness of 50 nm.…”

Quality assurance of test pieces as a basis for adequate significance of test results

“…The new method developed by [7] allows to determine contact strength and fracture toughness with relatively small test pieces which can be machined out of bigger components. Experiments showed for a variety of materials, that the characteristic inert strength in bending and under contact loading are in good agreement, while the scatter in the strength distribution is wider under contact loading [8]. Unexpected, contact strength test at low loading rates did not reveal the typical subcritical crack growth effect, as it was observed in bending tests [9].…”

Fatigue failure of coarse‐grained alumina under contact loading

“…2b versus the confidence intervals resulting from bending tests. It should be mentioned that the Weibull modulus m for contact strength is about half of that for bending strength [10,11].…”