scholarly journals The emergence of small-scale self-affine surface roughness from deformation

2020 ◽  
Vol 6 (7) ◽  
pp. eaax0847 ◽  
Author(s):  
Adam R. Hinkle ◽  
Wolfram G. Nöhring ◽  
Richard Leute ◽  
Till Junge ◽  
Lars Pastewka

Most natural and man-made surfaces appear to be rough on many length scales. There is presently no unifying theory of the origin of roughness or the self-affine nature of surface topography. One likely contributor to the formation of roughness is deformation, which underlies many processes that shape surfaces such as machining, fracture, and wear. Using molecular dynamics, we simulate the biaxial compression of single-crystal Au, the high-entropy alloy Ni36.67Co30Fe16.67Ti16.67, and amorphous Cu50Zr50 and show that even surfaces of homogeneous materials develop a self-affine structure. By characterizing subsurface deformation, we connect the self-affinity of the surface to the spatial correlation of deformation events occurring within the bulk and present scaling relations for the evolution of roughness with strain. These results open routes toward interpreting and engineering roughness profiles.

2021 ◽  
Vol 3 (4) ◽  
pp. 045042
Author(s):  
S Gowthaman ◽  
T Jagadeesha

Abstract High entropy alloy has offered significant attention in various material science applications, due to its excellent material features. In this investigation, the mechanical characteristics of Ni2FeCrCuAl High Entropy Alloy (HEA) have been examined under variable temperature and strain rates to analyze its influence over the material features of high entropy alloy through Molecular Dynamics (MD) simulation and it is stated that the formation of various point defects and dislocations are the major cause for the augmentation of tensile deformation which impacts the tensile behavior of high entropy alloy. Moreover, the Radial Distribution Function (RDF) has been examined throughout tensile deformation, to investigate the impact of applied stress over the de-bonding of various atoms and it is found that the strain rate has a greater beneficial impact over the material feature trailed by the temperature outcome, owed to its superior impact on the formation of point defects and shear strain during tensile characterization.


Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 889 ◽  
Author(s):  
Sanghita Mridha ◽  
Mageshwari Komarasamy ◽  
Sanjit Bhowmick ◽  
Rajiv Mishra ◽  
Sundeep Mukherjee

High entropy alloys (HEAs) have attracted widespread interest due to their unique properties at many different length-scales. Here, we report the fabrication of nanocrystalline (NC) Al0.1CoCrFeNi high entropy alloy and subsequent small-scale plastic deformation behavior via nano-pillar compression tests. Exceptional strength was realized for the NC HEA compared to pure Ni of similar grain sizes. Grain boundary mediated deformation mechanisms led to high strain rate sensitivity of flow stress in the nanocrystalline HEA.


RSC Advances ◽  
2020 ◽  
Vol 10 (16) ◽  
pp. 9187-9192 ◽  
Author(s):  
Hui Feng ◽  
Jingwen Tang ◽  
Haotian Chen ◽  
Yuanyuan Tian ◽  
Qihong Fang ◽  
...  

Using large-scale molecular dynamics (MD) simulations, the effects of interface and layer number in the nanoindentation response of experimentally observed nanotwinned Cu/high entropy alloy (HEA) FeCoCrNi nanolaminate are studied.


2021 ◽  
Vol 570 ◽  
pp. 151236
Author(s):  
Junye Li ◽  
Liguang Dong ◽  
Xiwei Dong ◽  
Weihong Zhao ◽  
Jianhe Liu ◽  
...  

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