Evolution of Adiabatic Shear Band in Ultra-Fine-Grained Iron under Dynamic Shear Loading

Ultra-fine-grained (UFG)/Nanocrystalline (NC) materials usually show reduced strain hardening and limited ductility due to formation of adiabatic shear band (ASB) under dynamic loading. In the present study, evolution of ASB in UFG Fe under dynamic shear loading was investigated. The UFG Fe was processed by equal-channel angular pressing (ECAP) via route Bc. After 6 passes, the grain size of UFG Fe reaches ~ 600 nm, as confirmed by means of Electron Back Scatter Diffraction (EBSD). Examination of micro-hardness and grain size of UFG Fe as a function of post-ECAP annealing temperature shows a transition from recovery to recrystallization at 500 0C. The high-strain-rate response of UFG Fe was characterized by hat-shaped specimen set-ups in Hopkinson bar experiments. The characteristics of ASB as a function of shear displacement, such as thickness of shear band and micro-hardness inside the shear band, were examined by SEM and Vickers micro-indentation respectively.

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Annealing effect on the evolution of adiabatic shear band under dynamic shear loading in ultra-fine-grained iron

International Journal of Impact Engineering ◽

10.1016/j.ijimpeng.2012.07.001 ◽

2012 ◽

Vol 50 ◽

pp. 1-8 ◽

Cited By ~ 15

Author(s):

Fuping Yuan ◽

Ping Jiang ◽

Xiaolei Wu

Keyword(s):

Shear Band ◽

Adiabatic Shear Band ◽

Shear Loading ◽

Adiabatic Shear ◽

Annealing Effect ◽

Dynamic Shear ◽

Fine Grained

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Influence of Different Material of Penetrator on Micro-Hardness of Steel Target

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.401-403.639 ◽

2013 ◽

Vol 401-403 ◽

pp. 639-642

Author(s):

Kai Wen Tian ◽

Li Jun Zhu ◽

Zhen Ming Wang ◽

Wen Lu Shi ◽

Min Ming Zou ◽

...

Keyword(s):

Plastic Deformation ◽

Shear Band ◽

Adiabatic Shear Band ◽

Hardness Test ◽

Adiabatic Shear ◽

Micro Hardness ◽

Glass Composite ◽

Microstructure Observation ◽

Steel Target ◽

Bulk Metallic Glass Composite

Contrast ballistic tests were carried out on 93W alloy and W fiber reinforced Zr-based bulk metallic glass composite. The influence of penetrator material on micro-hardness around target crater was studied using microstructure observation and micro-hardness test. The results show that adiabatic shear band appears in both targets after severe plastic deformation of impact. The effect of composite on micro-hardness of target is greater than that of W alloy, and the thickness with high micro-hardness around target crater formed by composite penetrator is 2.5 times than that by W alloy penetrator.

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Chip Formation Characteristics in High-Speed Machining of Hardened AISI1045 Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.565.484 ◽

2012 ◽

Vol 565 ◽

pp. 484-489

Author(s):

Bing Wang ◽

Zhan Qiang Liu ◽

Qi Biao Yang

Keyword(s):

Shear Band ◽

Chip Formation ◽

High Speed ◽

Adiabatic Shear Band ◽

Cutting Speed ◽

Adiabatic Shear ◽

High Speed Machining ◽

Micro Hardness ◽

Serrated Chip ◽

Aisi1045 Steel

Analyzing mechanism of the chip formation is a significant way to understand the metal cutting process better. The characterization of serrated chip formation in high speed machining of hardened AISI1045 steel is investigated with the aid of optical microscopy and micro-hardness measurement in this paper. The chip morphology evolving from continuous one to serrated one with the cutting speed increasing from 100-1500m/min is observed. Compared with the continuous chip pattern, serrated chip has its particular characterization parameters. The characteristics of serration degree and the segmentation frequency of the serrated chip are presented. The micro-hardness at the adiabatic shear band of serrated chip is then measured. The results show that the serration degree and segmentation frequency of serrated chip have a tendency of enhancement with the cutting speed increasing. The micro-hardness along the adiabatic shear band increases with the cutting speed increasing due to severe strain hardening. With a critical speed at about 100-200m/min, micro-hardness decreases from the tool-chip interface to the free surface of the chip.

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Effect of temperature and strain rate on the shear properties of Ti–6Al–4V alloy

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062c05505 ◽

2006 ◽

Vol 220 (2) ◽

pp. 127-136 ◽

Cited By ~ 11

Author(s):

W-S Lee ◽

C-F Lin ◽

S-Z Huang

Keyword(s):

Shear Band ◽

Strain Rate ◽

Adiabatic Shear Band ◽

Rate Sensitivity ◽

Adiabatic Shear ◽

Effect Of Temperature ◽

Dynamic Shear ◽

Shear Properties ◽

Current Test ◽

Split Hopkinson

This study uses the torsional split-Hopkinson bar to investigate the dynamic shear deformation and fracture behaviour of Ti–6Al–4V alloy under strain rates of 1800, 2300, and 2800 s−1 at temperatures ranging from −100 to 300 °C. It is found that both the strain rate and the temperature have a strong influence on the dynamic shear properties and fracture characteristics of the alloy. An increased strain rate and a reduced temperature cause the strain rate sensitivity to increase and the activation volume to decrease. However, the activation energy increases with decreasing shear stress and is found to attain a maximum value of 15 kJ/ mol under the current test conditions. The failure of the tested alloy is dominated by the formation of an adiabatic shear band. The characteristics of the adiabatic shear band and the fracture surface depend significantly on both the strain rate and the temperature.

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