Effect of loading direction and initial imperfections on the development of dynamic shear bands in a FCC single crystal

1995 ◽  
Vol 113 (1-4) ◽  
pp. 185-203 ◽  
Author(s):  
R. C. Batra ◽  
Z. G. Zhu
Keyword(s):  
Single Crystal ◽  
Shear Bands ◽  
Dynamic Shear ◽  
Initial Imperfections ◽  
Loading Direction

scholarly journals Dynamic Shear Deformation of a Precipitation Hardened Al0.7CoCrFeNi Eutectic High-Entropy Alloy Using Hat-Shaped Specimen Geometry

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 431
Author(s):  
Bharat Gwalani ◽  
Tianhao Wang ◽  
Abhinav Jagetia ◽  
Sindhura Gangireddy ◽  
Saideep Muskeri ◽  
...  
Keyword(s):  
Shear Deformation ◽  
Split Hopkinson Pressure Bar ◽  
Tensile Deformation ◽  
Shear Bands ◽  
Shear Loading ◽  
High Entropy Alloy ◽  
Local Dynamic ◽  
Dynamic Shear ◽  
High Entropy ◽  
Structural Applications

Lamellar eutectic structure in Al0.7CoCrFeNi high-entropy alloy (HEA) is emerging as a promising candidate for structural applications because of its high strength-ductility combination. The alloy consists of a fine-scale lamellar fcc + B2 microstructure with high flow stresses > 1300 MPa under quasi-static tensile deformation and >10% ductility. The response to shear loading was not investigated so far. This is the first report on the shear deformation of a eutectic structured HEA and effect of precipitation on shear deformation. A split-Hopkinson pressure bar (SHPB) was used to compress the hat-shaped specimens to study the local dynamic shear response of the alloy. The change in the width of shear bands with respect to precipitation and deformation rates was studied. The precipitation of L12 phase did not delay the formation of adiabatic shear bands (ASB) or affect the ASB width significantly, however, the deformed region around ASB, consisting of high density of twins in fcc phase, was reduced from 80 µm to 20 µm in the stronger precipitation strengthened condition. We observe dynamic recrystallization of grains within ASBs and local mechanical response of individual eutectic lamellae before and after shear deformation and within the shear bands was examined using nano-indentation.

Observation of kink shear bands in an aluminium single crystal fracture specimen

2009 ◽  
Vol 61 (5) ◽  
pp. 465-468 ◽  
Author(s):  
Swapnil D. Patil ◽  
R. Narasimhan ◽  
Raja K. Mishra
Keyword(s):  
Single Crystal ◽  
Shear Bands ◽  
Fracture Specimen ◽  
Crystal Fracture

Survival of Goss Grains during Cold Rolling of a Silicon Steel Single Crystal

2005 ◽  
Vol 495-497 ◽  
pp. 1061-1066 ◽  
Author(s):  
Dorothée Dorner ◽  
Ludger Lahn ◽  
Stefan Zaefferer
Keyword(s):  
Cold Rolling ◽  
Single Crystal ◽  
High Strain ◽  
Shear Bands ◽  
Rolling Process ◽  
Silicon Steel ◽  
Oriented Crystal ◽  
Cold Rolled ◽  
Goss Orientation ◽  
Crystal Volume

A silicon steel single crystal with initial Goss orientation, i.e. the {110}<001> orientation, was cold rolled up to 89 % thickness reduction. Most of the crystal volume rotates into the two symmetrical equivalent {111}<112> orientations. However, a weak Goss component is still present after high strain, although the Goss orientation is mechanically instable under plane strain loading. Two types of Goss-oriented crystal volumes are found in the highly deformed material. We suggest that their origin is different. The Goss-oriented regions that are observed within shear bands form during the cold rolling process. In contrast, those Goss-oriented crystal volumes that are found inside of microbands survive the cold rolling.

scholarly journals Microstructure and microtexture evolution of shear bands in Al–Cu single crystal during asymmetric rolling

2017 ◽  
Vol 128 ◽  
pp. 37-42 ◽  
Author(s):  
Xiaobin Guo ◽  
Yunlai Deng ◽  
Yong Zhang ◽  
Jin Zhang ◽  
Xinming Zhang
Keyword(s):  
Single Crystal ◽  
Shear Bands ◽  
Asymmetric Rolling ◽  
Microstructure And Microtexture

scholarly journals On Localized Deformation and Recrystallization as Damage Mechanisms during Thermomechanical Fatigue of Single Crystal Nickel-Based Superalloys

2011 ◽  
Vol 278 ◽  
pp. 357-362 ◽  
Author(s):  
Johan J. Moverare ◽  
Atsushi Sato ◽  
Sten Johansson ◽  
Magnus Hasselqvist ◽  
Roger C. Reed ◽  
...  
Keyword(s):  
Single Crystal ◽  
Power Plants ◽  
Deformation Behaviour ◽  
Shear Bands ◽  
Thermomechanical Fatigue ◽  
Deformation Bands ◽  
Localized Deformation ◽  
Damage Mechanisms ◽  
Tcp Phases

Thermomechanical fatigue (TMF) in superalloys is growing in importance due to the introduction of advanced cooling systems but also due to the changes in demand and competition within the power generation market; this is requiring many power plants to operate under cyclic conditions. In this paper the TMF behaviour of three different single crystal nickel-based superalloys are compared. It is demonstrated that the deformation and damage mechanisms occurring during TMF are rather different from those traditionally reported for creep or isothermal fatigue. In all cases examined, the deformation is localized within a rather small number of deformation bands. While these bands were found to consist mainly of micro-twins in some alloys, in others they might be better described as slip or shear bands. Furthermore, in some circumstances these bands are prone to recrystallization. In CMSX-4, the intersection points of twins of different orientation act as initiation sites for this process. In the SCA425 alloy – of smaller gamma’ content, lower creep resistance and less great oxidation resistance – twinning is observed infrequently; however the deformation is still very localized and in the distorted gamma-gamma’ microstructure, along the shear bands, recrystallization is observed. Furthermore the recrystallization is enhanced by oxidation due to the development of a gamma’-depleted zone. In CMSX-4, TCP phases precipitated during long term ageing cause a more dispersed deformation behaviour which prevents recrystallization. Our findings confirm the importance of an inhomogeneous microstructure for good TMF resistance.

Sign in / Sign up

Export Citation Format

Share Document