Microstructure evolution associated with adiabatic shear bands and shear band failure in ballistic plug formation in Ti–6Al–4V targets

2009 ◽  
Vol 516 (1-2) ◽  
pp. 205-216 ◽  
Author(s):  
L.E. Murr ◽  
A.C. Ramirez ◽  
S.M. Gaytan ◽  
M.I. Lopez ◽  
E.Y. Martinez ◽  
...  
Keyword(s):  
Shear Band ◽  
Microstructure Evolution ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
Band Failure ◽  
Plug Formation

Adiabatic Shear Localization in High Speed Cutting of Hardened Steel

2011 ◽  
Vol 55-57 ◽  
pp. 983-987 ◽  
Author(s):  
Chun Zheng Duan ◽  
Wei Sen Kong ◽  
Zhao Xi Wang ◽  
Min Jie Wang
Keyword(s):  
Shear Band ◽  
High Speed ◽  
Adiabatic Shear Band ◽  
Shear Bands ◽  
Cutting Speed ◽  
Shear Localization ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
High Speed Cutting ◽  
Serrated Chips

The formation and development of adiabatic shear localization in serrated chips have great significance to study of mechanism of high speed cutting. This paper investigates the theory prediction and experimental verification of the critical cutting speed of adiabatic shear localization, distribution of adiabatic shear band in serrated chip and the geometry of adiabatic shear band during high speed cutting of hardened steel. The results indicated that the theoretical prediction of critical cutting speed is consistent with the experimental results.With the increase of cutting speed, the width and spacing of adiabatic shear bands in the serrated chips decrease linearly. There are two types of adiabatic shear bands during the formation and development of adiabatic shear localization, i.e. the deformation shear band and the transformed shear band.

The Formation of Adiabatic Shear Band and Analysis of its Characteristics in the Process of Penetration

2012 ◽  
Vol 472-475 ◽  
pp. 2846-2849
Author(s):  
Jin Quan Li ◽  
Sheng Xu Wang
Keyword(s):  
Plastic Deformation ◽  
Shear Band ◽  
Steel Plate ◽  
Adiabatic Shear Band ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Stress And Strain ◽  
Adiabatic Shear Bands ◽  
Micro Cracks ◽  
Armor Steel

The characteristics and causes of the formation of adiabatic shear bands (ASB) in 30CrMnMo armor steel plate are analyzed by shooting 93W projectiles. The results show that adiabatic shear bands do not occur in the initial stages of the opening-crater and plugging. Adiabatic shear bands distributed sparsely appear in the stable penetrating phase because of the necessary strain volume. Adiabatic shear bands are formed along main shear stress lines at an angle of about 450 in relation to the penetrating direction. These are approximately consistent with the direction of the plastic deformation slip line. The non-homogenous deformation and centralizing of stress and strain inside the adiabatic shear band causes micro-cracks and micro-bores during cooling of the plate.

Effect of Die Forms on Rivet Deformation and Microstructure

2013 ◽  
Vol 634-638 ◽  
pp. 2827-2830
Author(s):  
Jiang Hua Deng ◽  
Chao Tang ◽  
Yan Ran Zhan ◽  
Xing Ying Jiang
Keyword(s):  
Shear Band ◽  
Experimental Method ◽  
Crack Formation ◽  
Radial Flow ◽  
Adiabatic Shear Band ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
Two Sides ◽  
Electromagnetic Riveting

In order to solve the problem of rivet head tending to crack in riveting, the effect of die forms on TA1 rivet deformation and microstructure was investigated by experimental method from macro and micro aspects in electromagnetic riveting. The results show that rivet material axial and radial flow can be controlled using different die forms, and thus the distribution of adiabatic shear band and grains in two sides of that in formed rivet head can be changed. With flat head die, severe axial and radial flows result in the nonuniform deformation and crack is prone to produced in rivet head. The adiabatic shear band of rivet head is obvious and grains in both sides of that deform severely. Material radial flows of rivet head are well constrained by spherical and 400 head die. The deformations are relatively uniform and the adiabatic shear bands are not obvious. It is an effective way to avoid crack formation and improve riveting quality using different die forms.

A FEM Study on Adiabatic Shear Band Formation in Tube Compression Driven by Electro-Magnetic Loading

2014 ◽  
Vol 566 ◽  
pp. 517-521 ◽  
Author(s):  
Xin Long Dong ◽  
Lai Ze Li ◽  
Ying Qian Fu ◽  
Feng Hua Zhou
Keyword(s):  
Shear Band ◽  
Shear Failure ◽  
Maximum Shear Stress ◽  
Shear Bands ◽  
Fem Simulation ◽  
Mechanical Analysis ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
Band Formation ◽  
Electro Magnetic

The adiabatic shear bands (ASB) of the thick-walled cylinder have been studied by many researchers in the recent years. The onset and evolutions of the multiple shear failure of metal cylinder under explosive loadings are affected by many factors such as the characteristics of the impulsive loadings, the dynamic behavior of the materials, etc. In this work, a tube compression driven by electro-magnetic forces is introduced, which enables to carry out the experiments of the spontaneous evolution of multiple adiabatic shear bands in metal tube. The FEM simulation was conducted to investigate the evolution process of strain localization with coupled thermo-mechanical analysis. The FEM results show that ASB initiates when the stress drops rapidly and strain growth and not when it reaches the maximum shear stress. Once the shear band is formed, elastic unloading occurs beside the shear band. The different behaviors of the damage introduced in the strain softening model affect the initial nucleation strain and the distribution of ASBs. With the increase of material damage softening, the initial strain of shear band decreases and the number of shear bands increases.

The Effect of Secondary Metalworking Processes on Susceptibility of Aircraft to Catastrophic Failures and Prevention Methods

2013 ◽  
Vol 58 (4) ◽  
pp. 1207-1212
Author(s):  
E.S. Dzidowski
Keyword(s):  
Dynamic Recovery ◽  
Fatigue Cracks ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
Deformation Mechanisms ◽  
Processing Maps ◽  
Adiabatic Shear Bands ◽  
Flow Localization ◽  
Catastrophic Failures ◽  
Prevention Methods

Abstract The causes of plane crashes, stemming from the subcritical growth of fatigue cracks, are examined. It is found that the crashes occurred mainly because of the negligence of the defects arising in the course of secondary metalworking processes. It is shown that it is possible to prevent such damage, i.e. voids, wedge cracks, grain boundary cracks, adiabatic shear bands and flow localization, through the use of processing maps indicating the ranges in which the above defects arise and the ranges in which safe deformation mechanisms, such as deformation in dynamic recrystallization conditions, superplasticity, globularization and dynamic recovery, occur. Thanks to the use of such maps the processes can be optimized by selecting proper deformation rates and forming temperatures.

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