Microstructural development of adiabatic shear bands formed by ballistic impact in a WELDALITE 049 alloy

The commercial pure titanium plate was shot vertically by the projectile with a diameter of 7.62mm at impact velocities ranging from 782m/s to 825m/s. The microstructure around the crater of commercial pure titanium plate was analyzed by optical microscopy (OM) and electron backscatter diffraction (EBSD) methods. It was found that different microstructures were observed along the depth of cater. In upper region of the crater, grains were deformed and fragmented. Adiabatic shear bands (ASBs) were observed in the middle of the crater, and some ASBs were bifurcated. At the bottom of the crater, the grains were less deformed, and the deformation twins were formed. The microstructures in the center of adiabatic shear band were mainly consisted of the dynamic recrystallization grains and sub-grains. The microstructure in the transition region was elongated grains along the shear stress distribution.

Download Full-text

Multiple Adiabatic Shear Bands in Ti–6Al–4V Targets under Ballistic Impact

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.581-582.448 ◽

2012 ◽

Vol 581-582 ◽

pp. 448-452

Author(s):

Kai Sun ◽

Xiao Dong Yu ◽

Shu Hua Li ◽

Cheng Wen Tan ◽

Fu Chi Wang

Keyword(s):

High Speed ◽

Impact Test ◽

Maximum Shear Stress ◽

Shear Bands ◽

Adiabatic Shear ◽

Ballistic Impact ◽

Adiabatic Shear Bands ◽

Steel Cylinder ◽

The Impact ◽

Good Agreement

In order to research the formation and spread of adiabatic shear bands in Ti-6Al-4V targets, LS-DYNA code is used to simulate the ballistic impact process. The projectile used in the impact test is a flat-headed steel cylinder with diameter of 7.62mm and length of 39mm. The results of simulated and impact test are in good agreement. Multiple adiabatic shear bands form in Ti-6Al-4V targets under high-speed ballistic impact. Adiabatic shear bands were found to extend parallel with a certain distance. The formation and distribution of adiabatic shear bands was related to the breaking-off of projectiles, which was caused by the distribution of maximum shear stress in Ti-6Al-4V targets and projectiles.

Download Full-text

Characterization of adiabatic shear bands in AM60B magnesium alloy under ballistic impact

Materials Characterization ◽

10.1016/j.matchar.2011.03.003 ◽

2011 ◽

Vol 62 (5) ◽

pp. 496-502 ◽

Cited By ~ 35

Author(s):

D.L. Zou ◽

L. Zhen ◽

C.Y. Xu ◽

W.Z. Shao

Keyword(s):

Magnesium Alloy ◽

Shear Bands ◽

Adiabatic Shear ◽

Ballistic Impact ◽

Adiabatic Shear Bands

Download Full-text

Microstructural development of adiabatic shear bands in ultra-fine-grained low-carbon steels fabricated by equal channel angular pressing

Materials Science and Engineering A ◽

10.1016/j.msea.2006.08.045 ◽

2006 ◽

Vol 441 (1-2) ◽

pp. 308-320 ◽

Cited By ~ 42

Author(s):

Byoungchul Hwang ◽

Sunghak Lee ◽

Yong Chan Kim ◽

Nack J. Kim ◽

Dong Hyuk Shin

Keyword(s):

Equal Channel Angular Pressing ◽

Shear Bands ◽

Carbon Steels ◽

Adiabatic Shear ◽

Microstructural Development ◽

Low Carbon ◽

Adiabatic Shear Bands ◽

Low Carbon Steels ◽

Fine Grained ◽

Angular Pressing

Download Full-text

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

Archives of Metallurgy and Materials ◽

10.2478/amm-2013-0152 ◽

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.

Download Full-text