TU Darmstadt / ULB / TUbiblio

Stress-driven grain boundary movement during nanoindentation in tungsten at room temperature

Javaid, Farhan and Durst, Karsten (2018):
Stress-driven grain boundary movement during nanoindentation in tungsten at room temperature.
In: Materialia, Elsevier Science Publishing, pp. 99-103, (1), [Online-Edition: https://doi.org/10.1016/j.mtla.2018.04.002],
[Article]

Abstract

Nanoindentations were performed in the vicinity of grain boundaries (GBs) in polycrystalline tungsten at room temperature, observing in some cases a secondary pop-in (known as GB pop-in) in the load–displacement curve. The dislocation microstructure in the plastic zone of the residual impression was analysed using sequential polishing, electron channelling contrast imaging (ECCI) and electron backscatter diffraction (EBSD) analysis on and below the surface. For some indentations, the interaction of the dislocations within the plastic zone and the GB leads to a localized GB movement on or below the surface. The occurrence and magnitude of GB movement are found to be strongly influenced by misorientation between the adjacent grains, the orientation of the indenter, as well as the applied load and the distance to the GB. The results show that the localized GB movement under an inhomogeneous stress field at room temperature is a possible deformation mechanism for tungsten.

Item Type: Article
Erschienen: 2018
Creators: Javaid, Farhan and Durst, Karsten
Title: Stress-driven grain boundary movement during nanoindentation in tungsten at room temperature
Language: English
Abstract:

Nanoindentations were performed in the vicinity of grain boundaries (GBs) in polycrystalline tungsten at room temperature, observing in some cases a secondary pop-in (known as GB pop-in) in the load–displacement curve. The dislocation microstructure in the plastic zone of the residual impression was analysed using sequential polishing, electron channelling contrast imaging (ECCI) and electron backscatter diffraction (EBSD) analysis on and below the surface. For some indentations, the interaction of the dislocations within the plastic zone and the GB leads to a localized GB movement on or below the surface. The occurrence and magnitude of GB movement are found to be strongly influenced by misorientation between the adjacent grains, the orientation of the indenter, as well as the applied load and the distance to the GB. The results show that the localized GB movement under an inhomogeneous stress field at room temperature is a possible deformation mechanism for tungsten.

Journal or Publication Title: Materialia
Number: 1
Publisher: Elsevier Science Publishing
Uncontrolled Keywords: Tungsten, Grain boundary movement, Dislocations, Nanoindentation, EBSD, ECCI
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Physical Metallurgy
Date Deposited: 06 Jun 2018 05:29
Official URL: https://doi.org/10.1016/j.mtla.2018.04.002
Export:

Optionen (nur für Redakteure)

View Item View Item