The role of shear instability in amorphization of cold-rolled NiTi

1990 ◽  
Vol 62 (4) ◽  
pp. 257-264 ◽  
Author(s):  
Jun-ichi Koike ◽  
D. M. Parkin ◽  
M. Nastasi
Keyword(s):  
Shear Instability ◽  
Cold Rolled

The Role of Temperature in Shear Instability and Bifurcation of Internally Pressurized Deep Boreholes

2017 ◽  
Vol 50 (11) ◽  
pp. 3003-3017 ◽  
Author(s):  
Manman Hu ◽  
Manolis Veveakis ◽  
Thomas Poulet ◽  
Klaus Regenauer-Lieb
Keyword(s):  
Shear Instability ◽  
Deep Boreholes

Fine-Grained Structures Associated with Deformation Twin and Its Influence on Tensile Behaviours in a Cold-Rolled Fe-Ni Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 895-900 ◽  
Author(s):  
Tatsuya Morikawa ◽  
Taku Moronaga ◽  
Kenji Higashida
Keyword(s):  
Deformation Twin ◽  
Liquid Nitrogen Temperature ◽  
Invar Alloy ◽  
High Yield ◽  
Fine Grained ◽  
Transmission Electron ◽  
Ni Alloy ◽  
Cold Rolled ◽  
Crystallographic Planes

Fine-grained structures in Fe-36mass%Ni Invar alloy have been investigated by using transmission electron microscopy (TEM). Particular attention has been paid on the role of deformation twinning in the formation of fine-grained structures and its influence on tensile stressstrain behaviours of rolled specimens. In Fe-Ni Invar alloy with a moderate stacking fault energy, deformation twin did not appear in usual cold-rolling at room temperature (RT), where a kind of cell walls was formed and the Cu-type texture was observed. On the other hand, twinning was occurred by rolling when specimens were cooled to liquid nitrogen temperature (LNT) immediately before the rolling. In such case, a fine lamellar structure was developed and the brass-type texture appeared. However, the lamella boundaries did not coincide with any crystallographic planes, and they were intersected with the bands of deformation twin. Specimens rolled by 90% in thickness reduction exhibited tensile stressstrain behaviours similar to those observed in specimens with SPD structures. In particular, specimens rolled at LNT showed high yield strengths and non-uniform deformation.

scholarly journals The role of nano-scaled structural non-uniformities on deformation twinning and stress-induced transformation in a cold rolled multifunctional β-titanium alloy

2020 ◽  
Vol 177 ◽  
pp. 181-185 ◽  
Author(s):  
Qianglong Liang ◽  
Zachary Kloenne ◽  
Yufeng Zheng ◽  
Dong Wang ◽  
Stoichko Antonov ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Deformation Twinning ◽  
Cold Rolled

scholarly journals Gravity Wave Emission by Shear Instability

2019 ◽  
Vol 49 (9) ◽  
pp. 2393-2406 ◽  
Author(s):  
Carsten Eden ◽  
Manita Chouksey ◽  
Dirk Olbers
Keyword(s):  
Gravity Wave ◽  
Single Layer ◽  
Internal Gravity Waves ◽  
Shear Instability ◽  
Vertical Shear ◽  
Wave Signal ◽  
Wave Emission ◽  
Balanced Flow ◽  
Single Layer Model

AbstractGravity wave emission by geostrophically balanced flow is diagnosed in numerical simulations of lateral and vertical shear instabilities. The diagnostic method in use allows for a separation of balanced flow and residual wave signal up to fourth order in the Rossby number (Ro). While evidence is found for a small but finite gravity wave emission from balanced flow in a single-layer model with large lateral shear and large Ro, a vertically resolved model with moderate velocity amplitudes appropriate to the interior ocean hardly shows any wave emission. Only when static instabilities generated by the shear instability of the balanced flow are allowed can a gravity wave signal similar to the ones reported in earlier studies be detected in the vertically resolved case. This result suggests a relatively small role of spontaneous wave emission in the classical sense of Lighthill radiation, and emphasizes the role of convective or symmetric instabilities during frontogenesis for the generation of internal gravity waves in the ocean and atmosphere.

scholarly journals Influence of Rare Earth Addition on Texture Development during Static Recrystallization and Mechanical Behaviour of Magnesium Alloy Sheets

2011 ◽  
Vol 702-703 ◽  
pp. 651-654
Author(s):  
Sang Bong Yi ◽  
Lilian Rayas ◽  
Stefanie Sandlöbes ◽  
Stefan Zaefferer ◽  
Dietmar Letzig ◽  
...  
Keyword(s):  
Rare Earth ◽  
Grain Growth ◽  
Static Recrystallization ◽  
Shear Bands ◽  
Rare Earth Addition ◽  
Axial Tensile ◽  
Sheet Formability ◽  
Cold Rolled ◽  
Basal Type

The role of rare earth addition on the microstructure and texture during recrystallization of cold rolled sheets is investigated by a comparative study of pure Mg, Mg-3Y and Mg1.5Nd sheets. In pure Mg, nucleation occurs mainly at shear bands which results in a texture weakening. The basal-type texture re-strengthens rapidly during grain growth of the pure Mg sheet. In contrast, in the Mg-RE alloys the weaker texture formed during early recrystallization strage is retained during further annealing due to retarded grain growth. Uni-axial tensile and Erichsen tests show that ductility and sheet formability are significantly improved by addition of rare earth elements.

Hot tensile behavior of cold-rolled Inconel 718 alloy at 650 °C: The role of δ phase

2018 ◽  
Vol 722 ◽  
pp. 136-146 ◽  
Author(s):  
Hongjun Zhang ◽  
Chong Li ◽  
Qianying Guo ◽  
Zongqing Ma ◽  
Yuan Huang ◽  
...  
Keyword(s):  
Inconel 718 ◽  
Tensile Behavior ◽  
Inconel 718 Alloy ◽  
Δ Phase ◽  
Cold Rolled

EBSD Investigation of Cold Rolled and Recrystallized Titanium

2013 ◽  
Vol 753 ◽  
pp. 289-292
Author(s):  
Mariusz Jedrychowski ◽  
Jacek Tarasiuk ◽  
Brigitte Bacroix
Keyword(s):  
Thermomechanical Treatment ◽  
Microstructure Evolution ◽  
Texture Evolution ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Topological Maps ◽  
Air Atmosphere ◽  
Commercially Pure ◽  
Cold Rolled

EBSD investigation of texture and microstructure evolution during a complete thermomechanical treatment of commercially pure titanium (HCP-Ti) is presented. Titanium was cold rolled to reach various degrees of thickness reduction: 20%, 40% and 60%. Next, annealing in air atmosphere was conducted at different conditions to achieve the recrystallized state. EBSD topological maps were measured on RD-TD and RD-ND surface of each sample. Strong heterogeneity of deformed titanium microstructures is described with focus on the important role of twinning mechanisms. Texture evolution in investigated titanium appears to be limited, especially in recrystallized state. However some subtle mechanisms are discussed.

Deciphering the role of multiple generations of annealing twins on texture evolution in cold-rolled high entropy alloys during annealing

2021 ◽  
Vol 205 ◽  
pp. 114221
Author(s):  
Lalit Kaushik ◽  
Jaiveer Singh ◽  
Joo-Hee Kang ◽  
Yoon Seok Ko ◽  
Dong-Ik Kim ◽  
...  
Keyword(s):  
Texture Evolution ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Multiple Generations ◽  
Annealing Twins ◽  
Cold Rolled
Sign in / Sign up

Export Citation Format

Share Document