In situ straining experiments were performed in a TEM on an equimolar CoCrFeMnNi (Cantor) high entropy alloy at room and cryogenic temperature. Perfect partial dislocation activity recorded both cases. Twinning directly follows the development of shearing that has various origins (perfect splitting, anchoring). It is shown that, although twinning more frequently observed liquid nitrogen tempera...

Thermodynamically consistent, three-dimensional (3D) phase field approach (PFA) for coupled multivariant martensitic transformations (PTs), including cyclic PTs, variant– variant transformations (i.e., twinning), and dislocation evolution is developed at large strains. One of our key points is in the justification of the multiplicative decomposition of the deformation gradient into elastic, tra...

Deformation mechanisms of a fully lamellar TiAl (γ lamellae: 100 ~ 300Ênm thick, α2 lamellae: 10 ~ 50 nm thick) crept at 760¡C have been investigated. It was found that, as a result of a fine structure, the motion and multiplication of dislocations within both γ and α2 lamellae are limited at low creep stresses (< 400 MPa). Thus, the glide and climb of lattice dislocations have insignificant co...

Abstract The temperature evolution of the Hall–Petch parameters for basal slip and twinning systems has been evaluated AZ31 alloy, using synchrotron radiation diffraction during compression tests from room to 473 K. alloy was processed following two processing routes, casting powder metallurgy, obtain different grain sizes with a similar strong fiber texture. Although macroscopic plasticity is ...

Deformation twinning, which occurs in fcc metals only under particular conditions of intrinsic material properties, microstructure, and loading conditions, occupies an indispensable place their deformation mechanism maps. Nonetheless, dedicated studies have seldom been carried out to explore the fundamental properties twinning dislocations mediating this process. Here we employ a combination at...

Deformation behavior of beryllium during compressive loading and cross-reloading is studied using in-situ high energy synchrotron X-ray diffraction microscopy crystal plasticity modeling. The evolution texture, twinning, elastic lattice strains, flow stress are measured compared with the predictions an advanced elastic-plastic self-consistent (EPSC) model. model initialized experimentally textu...

the dynamic behavior of three high manganese steels with very different stacking faultenergy (sfe) values (4-30 mj/m2) were studied using high strain rate torsional tests. the hotrolledmicrostructure of the steel with the lowest sfe of 4 mj/m2 consisted of a duplex mixture ofaustenite and ε-martensite, but those of the other two steels were fully austenitic. the deformedmicrostructures were stu...

A theoretical model for the plastic deformation of calcite, based on symmetry arguments and dislocation theory, is presented. Flow mechanisms suggested by the model conflict with those previously determined by Turner. Predictions from the model include translation gliding on e., ri, f and mI parallel to <110 ( i = 1,2,3; j = 1,2,3,4 ), and twin gliding on r (+) and (-) senses; s = 2.065, 0.630 ...

In situ tensile and reversed cyclic tests were run on a TWIP steel in SEM, with High-Resolution Digital Image Correlation (HR-DIC) measurements of the plastic strain field few selected grains prone to twinning, spatial resolution between 150 250 nm, or under an AFM, surface steps height at emerging deformation twins. Evidences detwinning upon load reversal, as well quantitative data twinning/de...