On the correlation between plastic strain and misorientation in polycrystalline body-centered-cubic microstructures with an emphasis on the grain size, loading history, and crystallographic orientation

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.

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The Effects of Processing on the Microstructure of Copper Thin Films on Tantalum Barrier Layers

MRS Proceedings ◽

10.1557/proc-391-303 ◽

1995 ◽

Vol 391 ◽

Cited By ~ 2

Author(s):

E.M. Zielinski ◽

R.P. Vinci ◽

J.C. Bravman

Keyword(s):

Thin Films ◽

Grain Size ◽

Barrier Layer ◽

Crystallographic Orientation ◽

Deposition Temperature ◽

Volume Fraction ◽

Fiber Texture ◽

Cu Films ◽

Barrier Layers ◽

Two Temperatures

abstractPreferred crystallographic orientation and grain size distribution were characterized as a function of processing for sputtered Cu films on Ta underlayers. The Ta barrier layer was deposited at two temperatures, 30 and 100 °C. Cu was deposited at 30, 150 and 250 °C on the 30 °C Ta, and at 100, 150, 200 and 250 °C on the 100 °C Ta. In the first set of samples, with increasing deposition temperature, the Cu (111) fiber texture grew weaker and the volume fraction of randomly oriented grains increased from 0.23 to 0.74. In contrast, for the films deposited on the 100 °C Ta, with increasing deposition temperature, Cu (111) fiber texture strengthened and the fractions of randomly oriented and twinned grains decreased. Grain size was lognormally distributed in all samples and varied approximately parabolically with deposition temperature. At a given deposition temperature, median grain size in the Cu was larger in the films deposited on the 100 °C Ta. These results will be related to the microstructure of the Ta underlayers. Cu microstructure on the 100 °C Ta is shown to be influenced by textural inheritance from the Ta underlayer. Microstructure of the Cu on 30 °C Ta is discussed in terms of trace contaminants.

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Microstructures and Tensile Properties of Electrodeposited Cu Sheets with Grain Sizes from Nanocrystalline to Ultrafine Scale

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.538-541.1611 ◽

2012 ◽

Vol 538-541 ◽

pp. 1611-1614

Author(s):

Han Zhuo Zhang ◽

Huiping Zhang ◽

Lei Liu

Keyword(s):

Grain Size ◽

Plastic Strain ◽

Strain Rate ◽

Tensile Properties ◽

Tensile Deformation ◽

Tensile Ductility ◽

Deformation Mechanisms ◽

Grain Sizes ◽

Low Strain Rate

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.

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The Effects of Grain Size, Dendritic Structure and Crystallographic Orientation on Fatigue Crack Propagation in IN713C Nickel-Based Superalloy

SSRN Electronic Journal ◽

10.2139/ssrn.3310264 ◽

2019 ◽

Cited By ~ 1

Author(s):

G. Liu ◽

S. Winwood ◽

K. Rhodes ◽

S. Birosca

Keyword(s):

Grain Size ◽

Fatigue Crack ◽

Crack Propagation ◽

Fatigue Crack Propagation ◽

Crystallographic Orientation ◽

Dendritic Structure ◽

Nickel Based Superalloy

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Investigation of the stress-strain state and microstructure transformation of copper busbars in the deformation zone during continuous extrusion

Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy) ◽

10.17073/0021-3438-2021-1-36-48 ◽

2021 ◽

Vol 1 (1) ◽

pp. 36-48

Author(s):

A. N. Koshmin ◽

A. V. Zinoviev ◽

A. Ya. Chasnikov ◽

G. N. Grachev

Keyword(s):

Grain Size ◽

Plastic Strain ◽

Deformation Zone ◽

Strain State ◽

Stress Strain ◽

Deformation Heating ◽

Stress Strain State ◽

The Press ◽

Metal Deformation ◽

Continuous Extrusion

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.

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