24 research outputs found
Achieving highly strengthened Al-Cu-Mg alloy by grain refinement and grain boundary segregation
Full text linkAn age-hardenable Al-Cu-Mg alloy (A2024) was processed by high-pressure
torsion (HPT) for producing an ultrafine-grained structure. The alloy was
further aged for extra strengthening. The tensile strength then reached a value
as high as ~1 GPa. The microstructures were analyzed by transmission electron
microscopy and atom probe tomography. The mechanism for the high strength was
clarified in terms of solid-solution hardening, cluster hardening, work
hardening, dispersion hardening and grain boundary hardening. It is shown that
the segregation of solute atoms at grain boundaries including subgrain
boundaries plays a significant role for the enhancement of the tensile
strength
Achieving highly strengthened Al–Cu–Mg alloy by grain refinement and grain boundary segregation
No full textInternational audienceAn age-hardenable Al-Cu-Mg alloy (A2024) was processed by high-pressure torsion (HPT) for producing an ultrafine-grained structure. The alloy was further aged for extra strengthening. The tensile strength then reached a value as high as ~1 GPa. The microstructures were analyzed by transmission electron microscopy and atom probe tomography. The mechanism for the high strength was clarified in terms of solid-solution hardening, cluster hardening, work hardening, dispersion hardening and grain boundary hardening. It is shown that the segregation of solute atoms at grain boundaries including subgrain boundaries plays a significant role for the enhancement of the tensile strength
In situ production of bulk intermetallic-based nanocomposites and nanostructured intermetallics by high-pressure torsion
No full textMicrostructural characteristics of tungsten-base nanocomposites produced from micropowders by high-pressure torsion
No full textPlastic deformation and allotropic phase transformations in zirconia ceramics during high-pressure torsion
No full textApplication of High-Pressure Torsion to WC–Co Ceramic-Based Composites for Improvement of Consolidation, Microstructure and Hardness
No full textAging Behavior of Ultrafine-Grained Al–Mg–Si–X (X = Cu, Ag, Pt, Pd) Alloys Produced by High-Pressure Torsion
No full textDevelopment of ultrahigh strength and high ductility in nanostructured iron alloys with lattice softening and nanotwins
No full textHigh-pressure torsion of TiFe intermetallics for activation of hydrogen storage at room temperature with heterogeneous nanostructure
No full textIatrogenic Colonic Perforation due to Computed Tomographic Colonography
No full textAlthough the complications of computed tomographic colonography (CTC) are very rare, CTC is associated with potential risk of colonic perforation. In the present report we describe two cases of colonic perforation secondary to CTC. In the first case with ascending colonic carcinoma, insertion of a rigid double-balloon catheter caused direct rectal wall perforation. In the second case with obstructive colonic carcinoma, pneumoperitoneum developed due to automated carbon dioxide insufflation. Both patients were asymptomatic after examination and recovered without any complications. Based on the findings of the current cases, we recommend that a soft-tip catheter be used for CTC, and suggest that colonic perforation can occur even with automatic insufflation, depending on patient characteristics
