scholarly journals Temperature Increases and Thermoplastic Microstructural Evolution in Adiabatic Shear-Bands in a High-Strength and High-Toughness 10 wt.% Ni Steel

2020 ◽  
Author(s):  
Sung-Il Baik ◽  
Ratnesh K. Gupta ◽  
K. Sharvan Kumar ◽  
David N. Seidman
Keyword(s):  
Microstructural Evolution ◽  
Shear Bands ◽  
High Strength ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
High Toughness

Microstructural Evolution from Shaped Charge through Steel Plates

2014 ◽  
Vol 566 ◽  
pp. 344-349
Author(s):  
M. Nabil Bassim ◽  
S. Boakye-Yiadom ◽  
Manon Bolduc
Keyword(s):  
Shock Wave ◽  
Molten Metal ◽  
Microstructural Evolution ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Shaped Charge ◽  
Steel Plates ◽  
Adiabatic Shear Bands ◽  
Armour Steel

A set of 18 armour steel plates were stacked on top of each other and subjected to shape charges that went through the plates and created a hole that decreased in diameter as it went through consecutive plates. Afterwards, the plates were examined and the hardness near the hole and away from the hole was taken to determine the effect of the passing of the shaped charge through the plates. Also, specimens from the walls of the holes were taken to determine changes in the microstructure due to the shock wave and the resulting excessive heating from the shape charge. It was observed that the shock wave produced significant changes in the microstructure resulting in the appearance adiabatic shear bands (ASBs). These ASBs persisted in holes in plates placed further down the stack (up to 8thin the stack). More complex microstructural mechanisms are thought to take place as opposed to erosion from the flow of the molten metal through the holes in the plates.

Analysis and characterization by electron backscatter diffraction of microstructural evolution in the adiabatic shear bands in Fe–Cr–Ni alloys

2009 ◽  
Vol 24 (8) ◽  
pp. 2617-2627 ◽  
Author(s):  
Huajie Yang ◽  
Yongbo Xu ◽  
Yasuaki Seki ◽  
Vitali F. Nesterenko ◽  
Marc André Meyers
Keyword(s):  
Microstructural Evolution ◽  
Electron Backscatter Diffraction ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
Localized Deformation ◽  
Ni Alloys ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Equiaxed Grains

The microstructural evolution inside adiabatic shear bands in Fe–Cr–Ni alloys dynamically deformed (strain rates > 104 s−1) by the collapse of an explosively driven, thick-walled cylinder under prescribed strain conditions was examined by electron backscatter diffraction. The observed structure within the bands consisted of both equiaxed and elongated grains with a size of ∼200 nm. These fine microstructures can be attributed to recrystallization; it is proposed that the elongated grains may be developed simultaneously with localized deformation (dynamic recrystallization), and the equiaxed grains may be formed subsequently to deformation (static recrystallization). These recrystallized structures can be explained by a rotational recrystallization mechanism.

Penetration Damaging Behavior of TB17 Titanium Alloy

2020 ◽  
Vol 993 ◽  
pp. 100-107
Author(s):  
Jing Li ◽  
Yun Peng Xin ◽  
Tao Jiang ◽  
Xin Nan Wang ◽  
Zhi Shou Zhu
Keyword(s):  
Titanium Alloy ◽  
Adiabatic Shear Band ◽  
Shear Bands ◽  
High Strength ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
Internal Wall ◽  
Micro Cracks ◽  
Opening Stage ◽  
River Pattern

The damage behavior of TB17 titanium alloy with ultra-high strength was studied by 12.7mm diameter armor piercing test. The characteristics and mechanism of damaging were analyzed by the observation of damage morphology of target board. The results indicated that the area was irregular at the opening stage, the internal wall were turtle-shell-like or poly-porous, a few cracks and no adiabatic shear band was observed. The zone was parabolic at the penetrating stage, the internal wall were granular or river pattern, adiabatic shear bands and fragments existed around the crater. A large number micro-pores and micro-cracks originating from the adiabatic shear bands expanded and formed macroscopic cracks. Finally, the target board fractured.

scholarly journals Dynamic failure of viscoplastic structures under ASB and micro-voiding

2018 ◽  
Vol 183 ◽  
pp. 01005
Author(s):  
Hannah Lois Dorothy ◽  
Patrice Longere
Keyword(s):  
Shear Banding ◽  
Shear Bands ◽  
High Strength ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Calibration Procedure ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
Adiabatic Shear Banding ◽  
Initial Boundary Value

Adiabatic shear bands are known to cause premature structural failure in high strength metals and alloys. The observation of adiabatic shear bands inside partially fractured specimens evidences the presence of micro-voids as the precursor of the ultimate failure. An enriched model containing the effects of adiabatic shear banding and micro-voiding mechanisms was developed and it is here taken through a calibration procedure. The aim of the present work is to evaluate the performances of the enriched model considering an initial-boundary value problem. To that purpose, the model has been implemented as user material in the engineering finite element computation code LS-DYNA. Numerical simulation of the dynamic shearing of hat shaped structures is conducted and the interest of accounting for the pre-failure stage consisting of micro-voiding in the ASB wake is emphasized.

Study on the Evolution of Adiabatic Shear Band of a High Strength Steel

2015 ◽  
Vol 782 ◽  
pp. 143-150
Author(s):  
Wen Wen Du ◽  
Qian Wang ◽  
Deng Hui Zhao ◽  
Lin Wang
Keyword(s):  
High Strength Steel ◽  
Split Hopkinson Pressure Bar ◽  
Shear Bands ◽  
High Strength ◽  
Heat Treatments ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
Hopkinson Pressure Bar ◽  
Static Tensile ◽  
Pressure Bar

The evolution process of a high strength steel which subjected with three different heat treatment proceedings and gets different quasi-static tensile properties was investigated in this paper. To precisely control the plastic deformation of the cylinder and capture the development process of adiabatic shear bands, stopper ring was used in Split Hopkinson Pressure Bar (SHPB). Combining the stress-strain curves and microstructures after SHPB tests, the microstructure evolution from the nucleation of adiabatic shear bands to fracture of the cylindrical steel were observed. The experimental results have demonstrated that there are similar fracture procedures of the steel treated through different heat treatments. Shear bands form firstly, then micro-cracks develop from shear bands, and lead to macro-crack finally. However, the critical strains for nucleation of ASBs and the time spending on the fracture procedure of the steel treated at different heat treatments are different. Samples treated at 900°C/AC exhibit the best resistance to adiabatic shear sensitivity when compressed under high strain rates.

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