Stacking fault energy and dynamic recovery: do they impact the indentation size effect?

2003 ◽  
Vol 358 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
A.A Elmustafa ◽  
D.S Stone
2012 ◽  
Vol 1424 ◽  
Author(s):  
D.E. Stegall ◽  
M.A. Mamun ◽  
A.A. Elmustafa

ABSTRACTWe investigated the effect of stacking fault free energy (SFE), on the magnitude of the indentation size effect (ISE) of several pure FCC metals using nanoindentation. The metals chosen were 99.999% Aluminum, 99.95% Nickel, 99.95% Silver, and 70/30 Copper Zinc (α-brass). Aluminum has a high SFE of about 200 mJ/ m2, whereas α -brass has a low SFE of less than 10 mJ/ m2. Nickel and Silver have intermediate SFE of about 128 mJ/ m2 and 22 mJ/m2 respectively. The SFE is an important interfacial characteristic and plays a significant role in the deformation of FCC metals due to its influence on dislocation movement and morphology. The SFE is a measure of the distance between partial dislocations and has a direct impact on the ability of dislocations to cross slip during plastic deformation. The lower the SFE the larger the separation between partial dislocations and thus cross slip and dynamic recovery are inhibited. The SFE impacts pure metals differently from alloys. It was discovered that the characteristic ISE behavior for the pure metals was different when compared to the α-brass which is an alloy. Several additional alloys were chosen for comparison including 7075 Aluminum and 70/30 Nickel Copper.


2019 ◽  
Vol 6 (2) ◽  
pp. 18-00545-18-00545
Author(s):  
Shota HASUNUMA ◽  
Hirohisa MIYAZAKI ◽  
Takeshi OGAWA

Author(s):  
A. Bandini ◽  
D. Chicot ◽  
P. Berry ◽  
X. Decoopman ◽  
A. Pertuz ◽  
...  

1995 ◽  
Vol 10 (11) ◽  
pp. 2908-2915 ◽  
Author(s):  
M. Atkinson

The variation of apparent hardness observed in previously reported Vickers indentation tests of metals is reexamined. Common deseriptions of the effect are shown to be inaccurate: the variation of apparent hardness is monotonic but not simple. The effect is consistent with varying size of a previously postulated “plastic hinge” at the perimeter of the indent. This complexity confers uncertainty on the estimation of characteristic macrohardness from small scale tests. Association of the indentation size effect with friction and with strain hardening is confirmed.


2008 ◽  
Vol 56 (14) ◽  
pp. 3338-3343 ◽  
Author(s):  
Ju-Young Kim ◽  
Seung-Kyun Kang ◽  
Julia R. Greer ◽  
Dongil Kwon

2015 ◽  
Vol 817 ◽  
pp. 706-711
Author(s):  
Yu Fei Shao ◽  
Xin Yang ◽  
Jiu Hui Li ◽  
Xing Zhao

Indenter size effect on the reversible incipient plasticity of Al (001) surface is studied by quasicontinuum simulations. Two cylindrical indenters with the radii 2.5nm and 17.5nm are used to penetrate the surface respectively, in displacement-control in steps of 0.02 nm. Results show that the plasticity under the small indenter is reversible, since it is dominated by the nucleation of a thin deformation twin, which can be fully removed after withdrawal of the indenter, due to the imaging force and stacking fault energy. Under the large indenter, multiple slip systems are activated simultaneously when incipient plasticity occurs, a few twin, dislocation and stacking fault ribbons still remain under the surface when the indenter has been completely retracted, thus the plasticity is irreversible.


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