Microstructure-Dependent Local Strain Behavior in Polycrystals through In-Situ Scanning Electron Microscope Tensile Experiments

Abstract

Digital image correlation of laser-ablated platinum nanoparticles on the surface of a polycrystalline metal (nickel-based superalloy Rene´88DT) was used to obtain the local strain behavior from an in-situ scanning electron microscope tensile experiment at room temperature. By fusing this information with crystallographic orientations from electron backscatter diffraction (EBSD), a subsequent analysis shows that the average maximum shear strain tends to increase with increasing Schmid factor. Additionally, the range of the extreme values for the maximum shear strain also increases closer to the grain boundary, signifying that grain boundaries and triple junctions accumulate plasticity at strains just beyond yield in polycrystalline Rene´88DT. In-situ experiments illuminating microstructure-property relationships of this ilk may be important for understanding damage nucleation in polycrystalline metals at high temperatures.

Direct powder forging of PM nickel-based superalloy: densification and recrystallisation

“…The powder billet was heated in a furnace to 1070°C, the usual deformation temperature for the FGH96 alloy [19,20], and soaked for 2 h to achieve uniform temperature distribution. Then the powder billet was transferred into the tooling within 40 s and was forged at a speed of 17 mm/s to the final shape.…”

Development of Biaxial Tensile Test System for <i>In-situ</i> Scanning Electron Microscope and Electron Backscatter Diffraction Analysis

“…[19][20][21][22] Tschopp et al 19) observed the microstructure-dependent local strain behavior during uniaxial tension in polycrystals of nickel based superalloy by in-situ SEM and also analyzed the crystallographic orientations by EBSD. They showed that the average maximum shear strain tended to increase with Schmid factor, and that the maximum shear strain near grain boundaries were large.…”

“…19) The grains with near {111} plane orientations tend to rotate to {111} plane orientations with the progress of deformation. This result corresponds to Fig.…”

Effect of Microstructure Variation on Differential Hardening Behavior of Steel Sheets under Biaxial Tensile State

“…The IPF maps show that the crystal orientation gradually varies with the progress of deformation depending on the grains and that the variation of orientation is relatively large near grain boundaries. 29) Especially for the circled grains with near {111} plane, the crystal orientations tend to vary from the near {111} plane (blue color) in ND to the near {221} plane (sky blue color), and the {111} plane texture was weakened. The value of GAM increases with the progress of deformation in the entire area of field frame.…”