The effect of grain size and plastic strain on slip length in 70-30 brass

1985 ◽  
Vol 16 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
H. Dong ◽  
A. W. Thompson
2010 ◽  
Vol 667-669 ◽  
pp. 991-996 ◽  
Author(s):  
Xu Zhang ◽  
A.E. Romanov ◽  
Elias C. Aifantis

Gradient nanomechanics is a generalized continuum mechanics framework accounting for “bulk-surface” interactions in the form of gradient terms that enter in the evolution equations of the relevant constitutive variables and/or in the governing field equations. This approach is discussed in the paper by developing appropriate differential equations for the plastic strain and/or the structural defects that bring this about. The effectiveness of the approach is illustrated by considering size-dependent stress-strain curves for nanopolycrystals with varying grain size.


2012 ◽  
Vol 538-541 ◽  
pp. 1611-1614
Author(s):  
Han Zhuo Zhang ◽  
Huiping Zhang ◽  
Lei Liu

Four types of Cu sheets, with average grain sizes of 200 nm, 90 nm, 33 nm and 11 nm respectively, were electrodeposited and tested by tension at both high and low strain rate. Typically, a higher strength with lower tensile ductility was obtained by increasing the strain rate or reducing the grain size till 33 nm. An inverse Hall-Petch result was found in 11 nm Cu, while 200 nm Cu exhibited an increase of both strength and plastic strain by the increment of strain rate. Tensile deformation mechanisms of the Cu sheets were also discussed with their microstructural features.


Author(s):  
A. N. Koshmin ◽  
A. V. Zinoviev ◽  
A. Ya. Chasnikov ◽  
G. N. Grachev

The paper describes an extensive study of features peculiar to physical and mechanical processes occurring in metal in the deformation zone during the continuous extrusion of Cu-ETP rectangular busbars 10×60 mm in size. Finite element computer simulation was used to obtain the values of extrusion power parameters. It was noted that moment and force values increase to the point of filling the press chamber free space with metal reaching a maximum of 12.26 kN·m and 1.54 MN, respectively. The stress-strain state analysis of metal in the deformation zone made it possible to obtain distribution fields of accumulated plastic strain, strain rate intensity and average stresses, and to build the graph of metal temperature variation over time during extrusion. Maximum levels of accumulated plastic strain and compressive stresses are observed in the contact zone of the workpiece with the press container abutment. The most intense metal deformation heating also occurs there. The comparison of modeling and microstructural study results indicate that a significant portion of the cast structure grinding work occurs at the entrance to the deformation zone and at the abutment zone subjected to the highest level of compression stresses. Metal deformation during the die passage leads to an oriented crystal structure formed with a grain size of 25–30 μm. Sample hardness measurement results are consistent with the results of structure analysis in the studied areas of the deformation zone. When the workpiece passes through the compression container abutment section, deformation heating occurs, which leads to a decrease in hardness from 93 to 67 HV. After the metal passes through the die, recrystallization processes continue in it leading to a slight increase in grain size and, accordingly, a decrease in hardness from 79 to 74 HV, which continues until the busbar contacts a cooling medium.


2012 ◽  
Vol 61 (4) ◽  
pp. 371-376 ◽  
Author(s):  
Kyohei NOMURA ◽  
Keiji KUBUSHIRO ◽  
Yohei SAKAKIBARA ◽  
Satoshi TAKAHASHI ◽  
Hiroki YOSHIZAWA

1996 ◽  
Vol 15 (16) ◽  
pp. 1381-1383 ◽  
Author(s):  
M. Z. Butt ◽  
N. Kauser ◽  
S. Akbar ◽  
S. S. Shaheed ◽  
M. Siddiq ◽  
...  

1975 ◽  
Vol 97 (4) ◽  
pp. 382-383 ◽  
Author(s):  
Amiya K. Chakrabarti ◽  
James A. Roberson ◽  
William R. Kerr

The strain-hardening exponent (n) is considered to be numerically equal to the uniform plastic strain for materials which exhibit a power low true stress true strain relation. In Ti-6Al-2Sn-4Zr-2Mo alloy a considerable deviation between the uniform plastic strain and the strain hardening exponent has been observed irrespective of the variations in microstructures and grain size. The present investigation indicates that a power law true stress true strain relation of the type σ = Kεn may not be valid for this material.


2005 ◽  
Vol 2005 (0) ◽  
pp. 561-562
Author(s):  
Kouichi YANASE ◽  
Shuji TAKASHIMA ◽  
Ryosuke MATSUMOTO ◽  
Michihiko NAKAGAKI

2001 ◽  
Vol 17 (12) ◽  
pp. 1580-1588 ◽  
Author(s):  
T. Inoue ◽  
S. Torizuka ◽  
K. Nagai ◽  
K. Tsuzaki ◽  
T. Ohashi
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