The structural evolution of PbSc(0.5)Nb(0.5)O(3) (PSN) under pressure has been studied by in situ powder neutron diffraction. Rietveld refinements to the data show that the continuous phase transition detected by x-ray diffraction at p(c) = 4.1 GPa (Maier et al 2010 Phys. Rev. B 81 174116) is associated with long-range ordering of antiphase octahedral tilts and local ordering of ferroic Pb displacements. Similar to PbSc(0.5)Ta(0.5)O(3) (PST) (Maier et al 2010 Acta Crystallogr. 66 280-91), antiphase octahedral tilting even exists below the critical pressure in a regime in which the structure retains a cubic metric. In contrast to PST, in which the Pb atomic displacement parameters (DPs) form ellipsoids elongated along the cubic {111} directions, the atomic DPs of Pb in PSN form flattened discs parallel to the cubic {111}-planes. This indicates that in PST the Pb displacements are along the cubic {111} directions, whereas in PSN the local Pb displacements are randomly distributed along the cubic {110} directions. The latter can be explained by the abundance of underbonded oxygen atoms associated with the chemical B-site disorder.

This study investigates the fatigue behavior of AlSi9Cu3 aluminum die‐cast alloy after exposure to accelerated corrosive conditions. It underscores the significant impact of minor localized corrosion imperfections on fatigue strength and presents a numerically efficient method for fatigue assessment based on fracture mechanics principles. Fatigue tests under rotary bending load showed a 34% reduction in long‐life fatigue strength for precorroded surfaces compared to polished ones. Numerical simulations, which treated the precorrosion as a single crack‐like surface imperfections, provided good estimates of fatigue life, when using the mean corrosion depth as initial flaw depth. Variations in the assessed fatigue strengths for different flaw geometries and sizes ranged from 13.7% above to 22.2% below the experimental values. The findings underscore the importance of incorporating short crack propagation, particularly for small corrosive defects, in fatigue assessments to enhance accuracy and ensure component reliability and safety when corrosion‐induced imperfections are present.

This study investigates the influence of pre-corrosion damage on the fatigue behavior of AlSi10MgMn high-pressure die-cast specimens, using the statistical distribution of corrosion depths. The analysis is conducted on two different surface conditions: an unmachined rough surface ($R_a=5.05$$\mathsf{\mu }\mathrm{m}$) and a machined, polished surface ($R_a=0.25$$\mathsf{\mu }\mathrm{m}$). For the unmachined specimens, the corrosive damage manifests as homogeneously spread localized corrosion, whereas the polished specimens exhibit less uniform but deeper corrosion. The average corrosion depth of the polished specimens is found to be slightly higher (313 $\mathsf{\mu }\mathrm{m}$ compared to 267 $\mathsf{\mu }\mathrm{m}$) with a broader depth distribution. Specimens are tested under a constant bending load amplitude in laboratory conditions at a stress ratio of $R=0$ until fracture. A fracture mechanics-based methodology is developed to assess the remaining fatigue life of corroded specimens, utilizing short and long crack fracture mechanical parameters derived from SENB specimens. This model incorporates a thickness reduction of the critical specimen cross-section based on the corrosion depth distribution and combines it with a small initial crack of the intrinsic defect size ($a_{eff}=14$$\mathsf{\mu }\mathrm{m}$). Regardless of the surface condition, using the most frequent corrosion depth for thickness reduction provides a good estimate of the long-life fatigue strength, while using the 90th percentile depth allows for a conservative assessment.