Control of the Mechanical Property on Machined Surface by a New Tool for Cutting-Burnishing Combined Process

2004 ◽  
Author(s):  
Toshiaki Segawa ◽  
Hiroyuki Sasahara ◽  
Masaomi Tsutsumi
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Compressive Residual Stress ◽  
Milling Process ◽  
Machined Surface ◽  
Combined Process ◽  
Machining Conditions ◽  
Residual Stress State ◽  
Key Factor ◽  
Resistance To Stress

We have developed a new tool that is called as the “Compressive Residual Stress Generating cutter” (CRSG cutter)[1]. The CRSG cutter can generate effective compressive residual stress within the machined surface concurrently with the milling process. It is expected to improve mechanical properties such as the fatigue life and the resistance to stress corrosion cracking. The purpose of this study is to investigate the possibility of controlling the residual stress state within the machined surface with varying the machining conditions using the CRSG cutter. It was shown that the quantity of the plastic deformation of the machined surface affects the residual stress. The setting of the machining conditions with the CRSG cutter can control the plastic deformation quantity. The cross feed width can change plastic deformation on the machined surface that is the key factor in order to control the residual stress within the machined surface.

Investigation into Influence of Cutting Fluid and Liquid Nitrogen on Machined Surface Residual Stress

2012 ◽  
Vol 566 ◽  
pp. 7-10 ◽  
Author(s):  
Meng Yang Qin ◽  
Bang Yan Ye ◽  
Bo Wu
Keyword(s):  
Residual Stress ◽  
Liquid Nitrogen ◽  
Cutting Fluid ◽  
Rough Machining ◽  
Surface Residual Stress ◽  
Dry Cutting ◽  
Machined Surface ◽  
Residual Stress State ◽  
Aisi 1045 Steel ◽  
1045 Steel

This paper gives the details of turning experiments on AISI 1045 steel by using various cutting fluid and liquid nitrogen condition. Residual stress on machined surface is generated in rough machining and fine machining with different rounded cutting edge radius. The effects of cutting fluid and liquid nitrogen on residual stress state are obtained by compared with dry cutting. Experimental results show that cutting fluid and liquid nitrogen have influence on machined residual stressl and liquid nitrogen generates residual compressive stress in all specimens.

Study on Pre-Stress Cutting of Bearing Race and Its Machined Surface State

2006 ◽  
Vol 532-533 ◽  
pp. 528-531 ◽  
Author(s):  
Bang Yan Ye ◽  
Bo Wu ◽  
Jian Ping Liu ◽  
Xiao Chu Liu ◽  
Xue Zhi Zhao
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Compressive Stress ◽  
Contact Fatigue ◽  
Residual Compressive Stress ◽  
Residual Tensile Stress ◽  
Machined Surface ◽  
Residual Stress State ◽  
Bearing Race ◽  
Hard Cutting

Theoretical analysis and experiments on bearing race show that a suitable residual compressive stress on roll path of bearing race can prolong its contact fatigue life. However, residual tensile stress is often found on workpiece surface of bearing race. To actively control the residual stress state and improve fatigue life of bearing part, a new method of pre-stress hard cutting is applied. In this paper, the principle of pre-stress hard cutting for bearing race is introduced as well as the experiments on it. In the experiments, residual stress, hardness and roughness of machined surface are measured and analyzed. Moreover, micro-topography and texture characteristics of machined surface are investigated and experimental results are compared with that by grinding. It is found that we can get residual compressive stress and fine quality on machined surface of bearing race by pre-stress hard cutting and increase its productivity as well.

On Predicting Residual Stress and Chip Morphology in Pre-Stressed Hard Turning

2010 ◽  
Author(s):  
Heping Wang ◽  
Shenfeng Wu ◽  
Xueping Zhang ◽  
C. Richard Liu
Keyword(s):  
Residual Stress ◽  
Temperature Distribution ◽  
Plastic Strain ◽  
Strain Distribution ◽  
Compressive Residual Stress ◽  
Hard Turning ◽  
Chip Morphology ◽  
Stress Conditions ◽  
Machined Surface ◽  
Plastic Strain Distribution

To analyze AISI 52100 steel response in hard turning under pre-stressed conditions, an explicit dynamic thermo-mechanical finite element model (FEM) has been developed. The FEM adopts Johnson-Cook constitutive model to describe the workpiece material property; and Johnson-Cook failure model as chip separation criterion; a modified coulomb’s friction law determines the friction behavior at the tool/chip interface. 500MPa of tensile and compressive pre-stress are imposed on the workpiece to simulate the pre-tension-stress and pre-compression-stress conditions respectively in hard turning. The effect of pre-stress on hard turning is determined by analyzing and comparing the simulation results under the three different pr-stress conditions, in terms of saw-tooth chip morphology, cutting forces, plastic strain distribution and temperature distribution on chip, plastic strain distribution and temperature distribution in machined surface, and especially the residual stress in machined surface. It identifies hard cutting under pretension-stress condition is an effective approach to generate a beneficial compressive residual stress profile in hard turning characterized by a bigger value of compressive residual stress and a deeper penetration depth into the hard turned surface which are helpful to enhance the fatigue life of machined components.

Investigation on Machined Surface Quality During Cutting of GH4169 Under High-Pressure Cooling

2020 ◽  
Vol 12 (7) ◽  
pp. 994-1003
Author(s):  
Ming-Yang Wu ◽  
Wei-Xu Chu ◽  
Ke-Ke Liu ◽  
Shu-Jie Wu ◽  
Yao-Nan Cheng
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
High Pressure ◽  
Tensile Stress ◽  
Surface Quality ◽  
Work Hardening ◽  
Surface Plastic ◽  
Residual Tensile Stress ◽  
Machined Surface ◽  
Machined Surface Quality

The aerospace component material GH4169 has low thermal conductivity and poor machinability, resulting in difficulty to guarantee good surface quality after conventional cutting. High-pressure cooling assisted machining technology can effectively improve the problem. In order to study the effect of high-pressure cooling assisted processing technology on the machined surface quality of GH4169, in this paper, Deform-3D was first used to construct a thermo-mechanical coupling finite element model for turning GH4169 under high-pressure cooling conditions, to analyze the turning temperature and surface residual stress. Then, analysis was carried out on the residual stress, work hardening behavior, and metamorphic layer of the GH4169 machined surface, in combination with the turning experiment. The results show that, under the conditions of little feeding and highspeed cutting, the GH4169 turning surface generates residual tensile stress along with both the feeding and turning directions. Moreover, the residual tensile stress gradually turns into the residual compressive stress along the depth direction. The application of high-pressure coolant can reduce the residual tensile stress of the machined surface. As the cooling pressure increases, the residual tensile stress of the machined surface decreases. The coupling effect between thermal deformation and plastic deformation when turning GH4169 can cause the work hardening of the surface, and the hardening degree decreases with the increase of cooling pressure. The high-pressure cooling assisted machining technology can effectively reduce surface plastic deformation, and promote the lessening of grain refinement degree of the material surface, thereby reducing the thickness of the metamorphic layer.

Plastic deformation and grain refinement in surface layer induced by thermo-mechanical loads for hard milling process

2018 ◽  
Vol 233 (10) ◽  
pp. 2033-2046 ◽  
Author(s):  
BinXun Li ◽  
Song Zhang ◽  
Jing Zhang
Keyword(s):  
Plastic Deformation ◽  
Grain Refinement ◽  
Surface Integrity ◽  
White Layer ◽  
Milling Process ◽  
Experimental Result ◽  
Plastic Deformation Zone ◽  
Hard Milling ◽  
Machined Surface ◽  
Mechanical Loads

Microstructure alteration of machined surface induced by the coupled thermal and mechanical loads in the hard milling process has great influence on surface integrity. Hence, it affects the performances of the workpiece. The hard milling experiments of AISI H13 steel with different cutting speeds and feed rates were carried out and the microstructure evolution of machined surface was investigated by means of some advanced characterization methods. The experimental result indicates that plastically deformed layer was evident with three distinguishable zones, that is, unaffected zone, plastic deformation zone, and white layer zone. X-ray diffraction analysis revealed that no retained austenite is detected in the white layer. Numerous nano-sized equiaxed grains were induced by dynamic recrystallization (DRX), as a result of severe shear plastic deformation on the machined surface. As the cutting speed increases, the grain refinement becomes more obvious. However, the original cementite was greatly refined and well distributed compared with bulk material. A significant improvement in nano-hardness was witnessed in both for machined surface and subsurface. The grain refinement as well as well-dispersed cementite played a vital role in the improvement of nano-hardness. The varied depth of plastic deformation was observed with respect to change of cutting forces. It is the main source of mechanical load inducing plastic deformation with the assistance of material thermal softening. The present work can provide more visibility on the surface integrity along with the quality control of the workpiece.

Study on the Cutting Force, Temperature and Residual Stress in Milling the New Rotor Steel

2010 ◽  
Vol 126-128 ◽  
pp. 923-928
Author(s):  
Ming Chen ◽  
Bin Zou ◽  
Shu Qiao Zhang ◽  
Bin Rong ◽  
Gang Liu
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Cutting Force ◽  
Cutting Forces ◽  
Morphological Characteristic ◽  
Cutting Temperature ◽  
Tensile Residual Stress ◽  
Rotor Steel ◽  
Machined Surface

According to the morphological characteristic of the new rotor steel, the cutting temperature and cutting forces generated by milling were investigated. The cutting temperature and forces resulted in the changes of the microstructure and residual stress of the machined surface. The tensile residual stress in the machined surface was affected more remarkably by the cutting temperature than cutting forces. In the microstructure of the machined surface, the larger plastic deformation in the machined surface and martensitic damage in the subsurface were also observed, which favored the higher tensile residual stress.

Influence of Compressive Stress to the Corrosion Rate of Magnesium

2016 ◽  
Vol 713 ◽  
pp. 284-287 ◽  
Author(s):  
Tetsuya Kawai ◽  
Noriyuki Takano
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Corrosion Rate ◽  
Mechanical Strength ◽  
Compressive Stress ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Elastic Stress ◽  
The Body ◽  
The Other

Magnesium has made an attention as implant material. Because it is decomposed and absorbed in the body, and its mechanical strength is stronger than that of polymers. It is, however, reported that the corrosion rate increases under the compressive elastic stress. In the other hand, it decreases in the specimen whose surface is applied to compressive residual stress by laser shot peening. This implies that compressive plastic deformation reduces the corrosion rate. In the present paper, the corrosion rate of magnesium that was plastically deformed by uniform high compressive stress was researched. As the result, the corrosion rate decreased as the compressive stress increased.

Assessment of the Effects of Microgrooved Cutting Tool on the Machining Induced Residual Stress in Machining of Ti-6Al-4V

2016 ◽  
Author(s):  
Changqing Qiu ◽  
Jianfeng Ma ◽  
Shuting Lei
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Compressive Residual Stress ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Three Dimensional ◽  
Rake Face ◽  
Machined Surface ◽  
Edge Distance ◽  
Cutting Inserts

In this paper, the effects of microgroove textured cutting tools on the residual stress on the machined surface of drying three-dimensional turning of Ti-6AL-4V are investigated using Finite Element Method (FEM). Microgrooves are designed and fabricated on the rake face of cemented carbide (WC/Co) cutting inserts. Specifically, the following microgroove parameters are examined: microgroove width, microgroove depth, and edge distance (the distance from cutting edge to the first microgroove). Their effects are assessed in terms of the circumferential residual stress. It is found that microgroove textured cutting tools can lower the detrimental tensile residual stress and induce beneficial compressive residual stress on the machined surface. The microgroove width, microgroove depth, and edge distance all have influence on residual stress on the machined surface in their own ways. This research provides insightful guidance for optimizing the fatigue life of the components by inducing beneficial compressive residual stress on the machined surface.

Study on Residual Stress Distribution in Surface Grinding

2011 ◽  
Vol 487 ◽  
pp. 49-53 ◽  
Author(s):  
Gui Cheng Wang ◽  
Chong Lue Hua ◽  
Ju Dong Liu ◽  
Hong Jie Pei ◽  
Gang Liu
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Phase Transformation ◽  
Material Properties ◽  
Residual Stress Distribution ◽  
Wheel Speed ◽  
Temperature History ◽  
Good Precision ◽  
Surface Residual Stress ◽  
Key Factor

The grinding process is currently used for most of the parts requiring good precision. However, the apparition of some damage related to this process is still uncontrolled. The major deterioration is from residual stress. In order to investigate the residual stresses caused by mechanical plastic deformation, thermal plastic deformation and phase transformation in ground components, a feasible numerical method was developed to accommodate appropriately thermal stress and phase transformation in a workpiece experiencing critical temperature variation during grinding. The change of the material properties was modeled as function of temperature history. The wheel velocityVsis a key factor in determining the distribution of residual stress; both the surface residual stress and the depth of residual stress are induced with the increase of the wheel speed.

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