1. BCC-FCC interfacial effects on plasticity and strengthening mechanisms in high entropy alloys
- Author
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Indranil Basu, Jeff Th. M. De Hosson, and Vaclav Ocelik
- Subjects
SOLID-SOLUTION ALLOY ,Materials science ,Yield (engineering) ,Polymers and Plastics ,MIGRATION ,Residual stress ,Dislocations ,CENTERED-CUBIC METALS ,02 engineering and technology ,DEFORMATION MECHANISMS ,Plasticity ,NANOINDENTATION ,ATOMISTIC SIMULATIONS ,01 natural sciences ,GRAIN-BOUNDARIES ,0103 physical sciences ,MULTILAYERS ,Composite material ,Strengthening mechanisms of materials ,010302 applied physics ,Interphase boundary ,High entropy alloys ,Metals and Alloys ,STRESS GRADIENTS ,Electron back scatter diffraction ,Nanoindentation ,021001 nanoscience & nanotechnology ,Electronic, Optical and Magnetic Materials ,Deformation mechanism ,Ceramics and Composites ,Grain boundary ,Deformation (engineering) ,0210 nano-technology - Abstract
Al0.7CoCrFeNi high entropy alloy (HEA) with a microstructure comprising strain free face-centered cubic (FCC) grains and strongly deformed sub-structured body centered cubic (BCC) grains was subjected to correlative nanoindentation testing, orientation imaging microscopy and local residual stress analysis. Depending on the geometry of BCC-FCC interface, certain boundaries indicated appearance of additional yield excursions apart from the typically observed elastic to plastic displacement burst. The role of interfacial strengthening mechanisms is quantified for small scale deformation across BCC-FCC interphase boundaries. An overall interfacial strengthening of the order of 4 G P a was estimated for BCC-FCC interfaces in HEAs. The influence of image forces due to the presence of a BCC-FCC interface is quantified and correlated to the observed local stress and hardness gradients in both the BCC and FCC grains.
- Published
- 2018
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