There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

J. Appl. Cryst.の発刊に際して

Welding Metallurgy of

Dynamic recrystallization behavior of a typical nickel-based superalloy during hot deformation

Effect of initial pH and temperature of iron salt solutions on formation of magnetite nanoparticles

On the widths of orientation gradient zones adjacent to grain boundaries

Development of novel grain morphology during hot extrusion of magnesium AZ21 alloy

AA-6061 aluminium alloys are used extensively in automobile and aerospace industries owing to their excellent combination of mechanical and physical properties. This alloy exhibits prominent anisotropy in mechanical properties when produced as cold rolled sheets. In manufacturing, sheet metal anisotropy may have severe consequences for downstream processes such as stamping and deep drawing operations. In the present study, correlations among in-plane anisotropy, strain path and formability of AA-6061 sheet metal are investigated. Using limit dome height tests, forming limit diagrams (FLDs) were constructed for three different sheet directions by applying appropriate strain localization and fracture criteria. For each sheet direction and strain path, microstructure and texture evolution were also observed to identify the origin of in-plane anisotropy and formability of the AA-6061 sheet metal alloy. A detailed analysis of microstructure under different strain paths suggests the direction and texture dependent yield locus to be a significant factor for in-plane anisotropy. Intra-granular crack propagation in a particular sheet direction (transverse direction: TD) may lead to reduced formability of AA-6061. Formability, on the other hand, appears to be highly correlated to the relative fraction of specific texture components. Certain critical texture components such as Cube {001} and Brass {011} influence the forming behaviour of AA-6061 aluminium alloy significantly.

Effect of microstructure and texture on forming behaviour of AA-6061 aluminium alloy sheet

A C-scan ultrasonic imaging system was used to investigate the microstructural evolution during dynamic recrystallization (DRX) of a 15Cr–15Ni–2.2Mo–Ti modified austenitic stainless steel (alloy D9). Four specimens were forged at 1273 K to different strains in the range 0.1–0.5. Specimens with true strains of 0.2 or lower did not show any variation in the amplitude of the first back-wall echo. However, a visible variation in the C-scan image was observed at and above the 0.3 strain level. This variation was attributed to the evolution of fine grains. The formation of fine grains was related to DRX, as indicated by electron backscattered diffraction. This study also revealed the characteristics of the DRX or ‘necklace grains’, as opposed to the so-called parent grains or rest of the microstructure.

Evolution and characterization of dynamically recrystallized microstructure in a titanium-modified austenitic stainless steel using ultrasonic and EBSD techniques

Sushil Mishra

Papers

On the widths of orientation gradient zones adjacent to grain boundaries

Development of novel grain morphology during hot extrusion of magnesium AZ21 alloy

Effect of microstructure and texture on forming behaviour of AA-6061 aluminium alloy sheet

Evolution and characterization of dynamically recrystallized microstructure in a titanium-modified austenitic stainless steel using ultrasonic and EBSD techniques

Forming limit diagram of Advanced High Strength Steels (AHSS) based on strain-path diagram