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| Abstract No.: |
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Scheduled at:
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Friday, May 06, 2022, Hall -2.32/33 2:40 PM
High Entropy Alloys II
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| Title: |
Systematic research on the formation of heterogenous microstructure in FeCoNiCrMn high entropy cold spray
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| Authors: |
Pengfei Yu* / Trinity College Dublin, Ireland
Rocco Lupoi / Trinity College Dublin, The University of Dublin, Ireland
Ningsong Fan/ Trinity College Dublin, The University of Dublin, Ireland
Shuo Yin/ Trinity College Dublin, The University of Dublin, Ireland
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| Abstract: |
High entropy alloys, as a novel alloy system, demonstrated excellent mechanical performance. However, , the strength-ductility trade-off effect still limit its performance. In recent decades, it has been found that heterogenous or gradient microstructure can efficiently solve the conflict. Cold spray is a promising method to create heterogenous microstructure with high efficiency and low cost. In this work, equiatomic FeCoNiCrMn HEA was deposited by cold spray and the microstructure was systematically investigated by transmission electron microscopy (TEM) and transmission Kikuchi diffraction (TKD). In cold spray, a gradient microstructure was formed and segregated Ni and Mn in starting particle were also redistributed. It is interesting that in the deformation of cold spray, grain structure can evolve synergistically with local composition variation, which is hardly found in the severe deformation of HEA by other methods. This phenomenon provides an alternative approach to design HEA gradient material. Moreover, twinned ultra-fine nanograins were detected in the region close to the impact interface. Compared with severe deformation of other low SFE metals, for FeCoNiCrMn HEA, twinning in nanograins was suppressed and postponed to higher stress condition due to its high shear modules brought by high lattice distortion effect.
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