scholarly journals 3D Simulation of Adiabatic Shear Bands in High Speed Machining

2007 ◽  
Author(s):  
Fabien Delalondre ◽  
Simon Guerdoux ◽  
Lionel Fourment
Keyword(s):  
High Speed ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
3D Simulation ◽  
High Speed Machining ◽  
Adiabatic Shear Bands

Microscopic Examination of Primary Shear Zone in High Speed Machining of Hardened High Strength Steel

2010 ◽  
Vol 97-101 ◽  
pp. 1887-1890 ◽  
Author(s):  
Chun Zheng Duan ◽  
Min Jie Wang ◽  
Tao Dou
Keyword(s):  
Shear Zone ◽  
High Strength Steel ◽  
High Speed ◽  
Shear Bands ◽  
Cutting Speed ◽  
High Strength ◽  
Optical Microscope ◽  
Adiabatic Shear ◽  
High Speed Machining ◽  
Adiabatic Shear Bands

The microstructure observation and microhardness measurement were performed on the adiabatic shear bands in primary shear zone in the serrated chips formed during high speed machining of two tempering hardness of hardened high strength steel under different cutting speeds by optical microscope, SEM, TEM and microhardness tester. The investigation results show that two types of adiabatic shear bands are formed as cutting speed increases. One is deformed band with heavy elongated microstructures generated under lower cutting speed, another is transformed band with fine grains under higher cutting speed. The increase of the cutting speed little influences on the microhardness in the transformed bands, and the microhardness in deformed band results from strain hardening, whereas transformation hardening leads to very high microhardness in transformed band.

An Investigation into the Microstructure of Adiabatic Shear Banding in AISI 1045 Hardened Steel due to High Speed Machining

2010 ◽  
Vol 154-155 ◽  
pp. 321-324 ◽  
Author(s):  
Chun Zheng Duan ◽  
Liang Chi Zhang ◽  
Hai Yang Yu ◽  
Min Jie Wang
Keyword(s):  
High Speed ◽  
Shear Banding ◽  
Shear Bands ◽  
Adiabatic Shear ◽  
High Speed Machining ◽  
Adiabatic Shear Bands ◽  
Adiabatic Shear Banding ◽  
Aisi 1045 ◽  
Cutting Speeds ◽  
Electronic Microscope

Adiabatic shear banding during high speed machining is important to understand material removal mechanisms. This paper investigates the microstructure of adiabatic shear bands (ASBs) in the serrated chips produced during the high speed machining of AISI 1045 hardened steel. Optical microscope, scanning electronic microscope(SEM) and transmission electronic microscope(TEM) were used to explore the microstructural characteristics. It was found that there are two types of adiabatic shear bands. One is the deformed adiabatic shear band composed of a significantly deformed structure generated in a range of low cutting speeds, and the other is the transformed adiabatic shear band composed of very small equiaxed grains generated under high cutting speeds. The results indicated that the deformed band has a tempered martensite structure that formed through large plastic deformation and the transformed band has experienced a dynamic recrystallization process.

Influence of Cutting Conditions on the Width of Adiabatic Shear Bands: An Investigation Using Finite Element Simulation

2013 ◽  
Vol 820 ◽  
pp. 194-199
Author(s):  
Tao Cui ◽  
Hong Wei Zhao ◽  
Ye Tian ◽  
Chuang Liu
Keyword(s):  
High Speed ◽  
Shear Bands ◽  
Chip Thickness ◽  
Rake Angle ◽  
Adiabatic Shear ◽  
Adiabatic Shear Bands ◽  
High Speed Cutting ◽  
Model Combining ◽  
Cutting Velocity ◽  
Microstructure Prediction

In this paper, a novel model combining the microstructure prediction model and a modified constitutive model of the Johnson-Cook (JC) model was developed and embedded into FEM software via the user subroutine. The chip formation and microstructure evolution in high speed cutting of Ti-6Al-4V alloy were simulated. The results indicated that dynamic recrystallization mainly happened in adiabatic shear bands (ASBs), where the grain size had a big decline. Then FEM simulations were carried out to investigate the effect of cutting velocity, uncut chip thickness, and the rake angle on the ASBs width of the serrated chips. It can be concluded that the width of ASB increases with the increasing of cutting depth and cutting velocity, and decreases with the increasing of rake angle of the tool.

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

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.

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 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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