scholarly journals Control of the Residual Stress within a Machined Surface using a Tool for Compressive Residual Stress Generation

2005 ◽  
Vol 71 (4) ◽  
pp. 496-500
Author(s):  
Toshiaki SEGAWA ◽  
Hiroyuki SASAHARA ◽  
Tatsuro ISHIKAWA ◽  
Hiroyuki MURASE ◽  
Masaomi TSUTSUMI
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Stress Generation ◽  
Machined Surface

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.

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.

Optimization of Tensile Residual Stress on Machined Surface in MQL Turning

2015 ◽  
Vol 713-715 ◽  
pp. 209-212 ◽  
Author(s):  
Xia Ji ◽  
Alexander H. Shih ◽  
Manik Rajora ◽  
Ya Min Shao ◽  
Steven Y. Liang
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Minimum Quantity Lubrication ◽  
Optimization Procedure ◽  
Stress Generation ◽  
Tool Geometry ◽  
Machined Surface ◽  
Good Surface ◽  
Optimal Inputs ◽  
Marquardt Algorithm

Producing good surface integrity is one of the main challenges of the machining industry. The increase of the utilization of minimum quantity lubrication (MQL) in order to reduce the amount of lubrication induced a lack of understanding of the physics behind the residual stress generation. Residual stress in the machined surface and subsurface is affected by materials, machining conditions, and tool geometry. These residual stresses could affect the service qualify and component life significantly. Residual stress can be determined by empirical or numerical experiments for selected configurations, even if both are expensive procedures. This paper presents a hybrid neural network that is trained using Simulated Annealing (SA) and Levenberg-Marquardt Algorithm (LM) in order to predict the values of residual stresses in cutting and radial direction after the MQL face turning process accurately. First, SA is used to train the weight and bias values of the ANN after which LM is used to fine tune the values trained by SA. Then, based on the predictions, an optimization procedure, using Genetic Algorithm (GA), is applied in order to find the best cutting conditions. At each generation, GA suggests a population of inputs that are then sent to the trained ANN in order to predict the residual stresses. The objective is to find the optimal inputs that minimize the tensile stress on the machined surface.

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.

Experimental Study on Prestressed Cutting of Alloy Ring Parts

2016 ◽  
Vol 836-837 ◽  
pp. 71-76
Author(s):  
Rui Tao Peng ◽  
Yang Ge Li ◽  
Xin Zi Tang ◽  
Zhuan Zhou
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Stress Distribution ◽  
Cutting Force ◽  
Surface Integrity ◽  
Compressive Residual Stress ◽  
Machining Process ◽  
Residual Tensile Stress ◽  
Machined Surface ◽  
Cutting Method

In order to solve the poor cutting performance for the titanium alloy and the serious residual tensile stress distribution on the machined surface in cutting titanium alloy, the utilization of prestressed cutting method is proposed to actively control the residual stress distribution status on the machined surface in machining process. Titanium alloy ring parts were pre-stretched at different condition by a lathe-specific pretension device respectively. By the cutting experimental, the cutting force ,chip formation and surface integrity indexes are compared and studied. The results show that in suitable compressive residual stress on machined surface are achieved by utilizing the prestressed cutting method ,meanwhile procedures of residual stress adjustment after machining could be omitted. Furthermore, the magnitude of compressive residual stress could be actively controlled by adjusting the magnitude of prestressed force in certain extent. And uniform saw-tooth chip are generated in prestressed cutting, meanwhile there’s no significant increment of cutting force. Prestressed cutting method could generate good surface integrity.

Monitoring of mechanical properties of prestressed glass fiber epoxy composites over 12 months after fabrication

2021 ◽  
pp. 002199832110047
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Flexural Strength ◽  
Compressive Residual Stress ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Epoxy Composites ◽  
Flexural Properties ◽  
Initial Increase ◽  
Fiber Volume

Fiber prestressing during matrix curing can significantly improve the mechanical properties of fiber-reinforced polymer composites. One primary reason behind this improvement is the generated compressive residual stress within the cured matrix, which impedes cracks initiation and propagation. However, the prestressing force might diminish progressively with time due to the creep of the compressed matrix and the relaxation of the tensioned fiber. As a result, the initial compressive residual stress and the acquired improvement in mechanical properties are prone to decline over time. Therefore, it is necessary to evaluate the mechanical properties of the prestressed composites as time proceeds. This study monitors the change in the tensile and flexural properties of unidirectional prestressed glass fiber reinforced epoxy composites over a period of 12 months after manufacturing. The composites were prepared using three different fiber volume fractions 25%, 30%, and 40%. The results of mechanical testing showed that the prestressed composites acquired an initial increase up to 29% in the tensile properties and up to 32% in the flexural properties compared to the non-prestressed counterparts. Throughout the 12 months of study, the initial increase in both tensile and flexural strength showed a progressive reduction. The loss ratio of the initial increase was observed to be inversely proportional to the fiber volume fraction. For the prestressed composites fabricated with 25%, 30%, and 40% fiber volume fraction, the initial increase in tensile and flexural strength dropped by 29%, 25%, and 17%, respectively and by 34%, 26%, and 21%, respectively at the end of the study. Approximately 50% of the total loss took place over the first month after the manufacture, while after the sixth month, the reduction in mechanical properties became insignificant. Tensile modulus started to show a very slight reduction after the fourth/sixth month, while the flexural modulus reduction was observed from the beginning. Although the prestressed composites displayed time-dependent losses, their long-term mechanical properties still outperformed the non-prestressed counterparts.

scholarly journals Influence of Preaging Temperature on the Indentation Strength of 3Y-TZP Aged in Ambient Atmosphere

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2767
Author(s):  
Ki-Won Jeong ◽  
Jung-Suk Han ◽  
Gi-Uk Yang ◽  
Dae-Joon Kim
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Low Temperature ◽  
Compressive Residual Stress ◽  
Yttria Stabilized Zirconia ◽  
Ambient Atmosphere ◽  
Aged Specimen ◽  
Stabilized Zirconia ◽  
M Phase ◽  
The Relationship

Yttria-stabilized zirconia (3Y-TZP) containing 0.25% Al2O3, which is resistant to low temperature degradation (LTD), was aged for 10 h at 130–220 °C in air. The aged specimens were subsequently indented at loads ranging from 9.8 to 490 N using a Vickers indenter. The influence of preaging temperature on the biaxial strength of the specimens was investigated to elucidate the relationship between the extent of LTD and the strength of zirconia restorations that underwent LTD. The indented strength of the specimens increased as the preaging temperature was increased higher than 160 °C, which was accompanied by extensive t-ZrO2 (t) to m-ZrO2 (m) and c-ZrO2 (c) to r-ZrO2 (r) phase transformations. The influence of preaging temperature on the indented strength was rationalized by the residual stresses raised by the t→m transformation and the reversal of tensile residual stress on the aged specimen surface due to the indentation. The results suggested that the longevity of restorations would not be deteriorated if the aged restorations retain compressive residual stress on the surface, which corresponds to the extent of t→m phase transformation less than 52% in ambient environment.

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