The Constituent Phases and Micromechanical Properties of Steel Corrosion Layers Generated by Hyperbaric-Oxygen Accelerated Corrosion Test.

Hyperbaric oxygen-accelerated corrosion testing (HOACT) is a newly developed method to study in the labor the corrosion behavior of steel bars in concrete. This work aimed to intensively investigate the mechanical properties and microstructures of HOACT-generated corrosion products by means of nano-indentation tests, Raman micro-spectrometry, and scanning electron microscopy. The local elastic modulus and nanohardness varied over wide ranges of 6.

A strategy of designing high-entropy alloys with high-temperature shape memory effect.

Shape memory effect, the ability to recover a pre-deformed shape on heating, results from a reversible martensitic transformation between austenite and martensite phases. Here, we demonstrate a strategy of designing high-entropy alloys (HEAs) with high-temperature shape memory effect in the CrMnFeCoNi alloy system. First, we calculate the difference in Gibbs free energy between face-centered-cubic (FCC) and hexagonal-close-packed (HCP) phases, and find a substantial increase in thermodynamic equilibrium temperature between the FCC and HCP phases through composition tuning, leading to thermally- and stress-induced martensitic transformations.

Twinning behavior of orthorhombic-α" martensite in a Ti-7.5Mo alloy.

Deformation microstructure of orthorhombic-α" martensite in a Ti-7.5Mo (wt.%) alloy was investigated by tracking a local area of microstructure using scanning electron microscopy, electron back-scattered diffraction, and transmission electron microscopy.

Quantitative analysis of {332}〈113〉 twinning in a Ti-15Mo alloy by scanning electron microscopy.

We have performed quantitative analysis of {332}〈113〉 twinning in a β-Ti-15Mo (wt.%) alloy by scanning electron microscopy and electron backscattering diffraction (EBSD). Microstructure-twinning relations were evaluated by statistical analysis of the evolving twin structure upon deformation at room temperature.

Study of {332}<113> twinning in a multilayered Ti-10Mo-xFe (x = 1-3) alloy by ECCI and EBSD.

We have investigated the propagation of {332}<113> twins in a multilayered Ti-10Mo-xFe (x = 1-3) alloy fabricated by multi-pass hot rolling. The material contains a macroscopic Fe-graded structure (about 130 μm width) between 1 and 3 wt% Fe in the direction perpendicular to rolling. We observe strong influence of the Fe-graded structure in the twin propagation behavior.

Microstructure study of a severely plastically deformed Mg-Zn-Y alloy by application of low angle annular dark field diffraction contrast imaging.

Microstructural investigation of extremely strained samples, such as severely plastically deformed (SPD) materials, by using conventional transmission electron microscopy techniques is very challenging due to strong image contrast resulting from the high defect density. In this study, low angle annular dark field (LAADF) imaging mode of scanning transmission electron microscope (STEM) has been applied to study the microstructure of a Mg-3Zn-0.5Y (at%) alloy processed by high pressure torsion (HPT).

Longitudinal Hierarchy Co3O4 Mesocrystals with High-dense Exposure Facets and Anisotropic Interfaces for Direct-Ethanol Fuel Cells.

Novel electrodes are needed for direct ethanol fuel cells with improved quality. Hierarchical engineering can produce catalysts composed of mesocrystals with many exposed active planes and multi-diffused voids. Here we report a simple, one-pot, hydrothermal method for fabricating Co3O4/carbon/substrate electrodes that provides control over the catalyst mesocrystal morphology (i.

Cytocompatibility evaluation and surface characterization of TiNi deformed by high-pressure torsion.

Effect of high-pressure torsion (HPT) deformation on biocompatibility and surface chemistry of TiNi was systematically investigated. Ti-50 mol% Ni was subjected to HPT straining for different numbers of turns, N=0.25, 0.

Effect of high-pressure torsion deformation on surface properties and biocompatibility of Ti-50.9 mol. %Ni alloys.

Ti-50.9 mol. %Ni was subjected to high-pressure torsion (HPT) deformation for different number of rotations (N) of 0.

First-principles study of electronic structures and stability of body-centered cubic Ti-Mo alloys by special quasirandom structures.

The electronic structures and structural properties of body-centered cubic Ti-Mo alloys were studied by first-principles calculations. The special quasirandom structures (SQS) model was adopted to emulate the solid solution state of the alloys. The valence band electronic structures of Ti-Mo and Ti-Mo-Fe alloys were measured by hard x-ray photoelectron spectroscopy.

Low temperature heat capacity of a severely deformed metallic glass.

The low temperature heat capacity of amorphous materials reveals a low-frequency enhancement (boson peak) of the vibrational density of states, as compared with the Debye law. By measuring the low-temperature heat capacity of a Zr-based bulk metallic glass relative to a crystalline reference state, we show that the heat capacity of the glass is strongly enhanced after severe plastic deformation by high-pressure torsion, while subsequent thermal annealing at elevated temperatures leads to a significant reduction. The detailed analysis of corresponding molecular dynamics simulations of an amorphous Zr-Cu glass shows that the change in heat capacity is primarily due to enhanced low-frequency modes within the shear band region.