Effect of Strain Rate Sensitivity and Strain Hardening Exponent of Materials on Plastic Strain Distribution and Damage Accumulation During Equal Channel Angular Pressing

2018 ◽  
Vol 43 (S1) ◽  
pp. 831-844
Author(s):  
Mehdi Shaban Ghazani ◽  
Behzad Binesh ◽  
Ali Fardi-Ilkhchy
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Strain Hardening ◽  
Equal Channel Angular Pressing ◽  
Strain Rate Sensitivity ◽  
Strain Distribution ◽  
Damage Accumulation ◽  
Rate Sensitivity ◽  
Strain Hardening Exponent ◽  
Angular Pressing

Effects of strain hardenability and strain-rate sensitivity on the plastic flow and deformation homogeneity during equal channel angular pressing

2001 ◽  
Vol 16 (3) ◽  
pp. 856-864 ◽  
Author(s):  
Hyoung Seop Kim ◽  
Sun Ig Hong ◽  
Min Hong Seo
Keyword(s):  
Strain Rate ◽  
Strain Hardening ◽  
Plastic Flow ◽  
Equal Channel Angular Pressing ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Strain Hardening Exponent ◽  
Angular Pressing ◽  
Deformation Inhomogeneity ◽  
Method Analysis

The effects of strain hardenability and strain rate sensitivity on the plastic flow and deformation inhomogeneity during equal channel angular pressing were studied using a finite element method analysis. In this study, perfect plastic nonhardening and rate-insensitive materials, and rate-sensitive materials were considered. In case of the nonhardening and rate-insensitive materials, the deformed geometry was predicted to be quite uniform and homogeneous. Deformation inhomogeneity developed, however, in materials with finite work-hardening exponent and strain-rate sensitivity. The corner gap formed in strain-hardening materials whereas the upper and lower channel gaps formed in strain-rate-sensitive materials. The deformation inhomogeneity was strongly dependent on the relative effects of strain-hardening exponent and strain-rate sensitivity. The predictions on the deformation inhomogeneity and the formation of corner and channel gaps were compatible with the experimental data published in the literature.

Local Investigations of the Mechanical Properties of Ultrafine Grained Metals by Nanoindentations

2006 ◽  
Vol 503-504 ◽  
pp. 31-36 ◽  
Author(s):  
Johannes Mueller ◽  
Karsten Durst ◽  
Dorothea Amberger ◽  
Matthias Göken
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Room Temperature ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Fcc Metals ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Indentation Strain

The mechanical properties of ultrafine-grained metals processed by equal channel angular pressing is investigated by nanoindentations in comparison with measurements on nanocrystalline nickel with a grain size between 20 and 400 nm produced by pulsed electrodeposition. Besides hardness and Young’s modulus measurements, the nanoindentation method allows also controlled experiments on the strain rate sensitivity, which are discussed in detail in this paper. Nanoindentation measurements can be performed at indentation strain rates between 10-3 s-1 and 0.1 s-1. Nanocrystalline and ultrafine-grained fcc metals as Al and Ni show a significant strain rate sensitivity at room temperature in comparison with conventional grain sized materials. In ultrafine-grained bcc Fe the strain rate sensitivity does not change significantly after severe plastic deformation. Inelastic effects are found during repeated unloading-loading experiments in nanoindentations.

Finite Deflections of a Rigid-Viscoplastic Strain-Hardening Annular Plate Loaded Impulsively

1968 ◽  
Vol 35 (2) ◽  
pp. 349-356 ◽  
Author(s):  
Norman Jones
Keyword(s):  
Strain Rate ◽  
Strain Hardening ◽  
Strain Rate Sensitivity ◽  
Annular Plate ◽  
Dominant Role ◽  
Plate Thickness ◽  
Rate Sensitivity ◽  
Finite Deflections ◽  
Analytical Treatment ◽  
Rigid Plastic

A relatively simple analytical treatment of the behavior of a rigid-plastic annular plate subjected to an initial linear impulsive velocity profile is presented. The influence of finite deflections has been included in addition to strain-hardening and strain-rate sensitivity of the plate material. It is shown, for deflections up to the order of twice the plate thickness, that strain-hardening is unimportant, strain-rate sensitivity has somewhat more effect, while membrane forces play a dominant role in reducing the permanent deflections.

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