Study Progress on Grinding Surface Residual Stresses for Nano-Ceramic Coatings

2013 ◽  
Vol 753-755 ◽  
pp. 277-280 ◽  
Author(s):  
Wei Xiang Liu
Keyword(s):  
Residual Stress ◽  
High Hardness ◽  
Ceramic Materials ◽  
Ceramic Coatings ◽  
Grinding Process ◽  
Monitoring And Control ◽  
Surface Residual Stress ◽  
Surface Residual Stresses ◽  
Process Monitoring And Control ◽  
Grinding Mechanism

Nano-ceramic materials had high hardness and wear resistance. Combined with current technology and cost saving, nanostructured coatings technology were carried out, using HVOF ( high velocity oxygen fuel) or plasma spraying technique can obtain high quality ceramic coating on metal substrate. Ceramic coatings produced cracks in the grinding due to grinding surface residual stress. the coatings grinding surface residual stress of engineering ceramics have been researched, grinding surface residual stress in the nanostructured ceramic coatings are being researched. the researches in this field include grinding process modeling, abrasives and grinding parameters, grinding process monitoring and control and realization of the software, the grinding mechanism and grinding damage on the surface, grinding force prediction, on-line detection, grinding on nanocoating material is a multivariable complex process.

A Detection Method for Grinding Surface Residual Stresses on Nanostructured Ceramic Coatings

2013 ◽  
Vol 341-342 ◽  
pp. 179-182
Author(s):  
Wei Xiang Liu
Keyword(s):  
Residual Stress ◽  
Crystal Orientation ◽  
Detection Method ◽  
Ceramic Coatings ◽  
X Ray Diffraction ◽  
Surface Residual Stress ◽  
X Ray ◽  
Surface Residual Stresses ◽  
Nanostructured Ceramic ◽  
Distance Change

The surface of the nanostructured ceramic coatings after grinding appears cracks, these cracks will reduce components intensity, and the cause of these cracks is grinding surface residual stress. The surface residual stress makes the distance change regularly with crystal orientation and stress changing on the cognate crystal plane of different crystal grain, therefore the X ray diffraction line offset, according to the size of the offseted position, the residual stress can be calculated by using σ = K • M.

Study on the Correlativity between Grinding Parameters and Surface Residual Stresses in Ceramic

2008 ◽  
Vol 375-376 ◽  
pp. 480-484 ◽  
Author(s):  
Guang Xiu Zhang ◽  
Bin Lin ◽  
Zhen Peng Shi
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Mechanical Effect ◽  
Diffraction Measurement ◽  
Depth Of Penetration ◽  
Surface Residual Stress ◽  
Grinding Parameters ◽  
Surface Residual Stresses ◽  
Element Simulation

The generation and distribution of workpiece surface and sub-surface residual stress were predicted through the dynamic finite element simulation of the grinding ceramic process. The base of the simulation is that the thermo elastic-plastic finite element theory and the coupling of grinding forces and temperature were adopted. The results obtained from X-ray diffraction measurement compared well with the values calculated from theory. The correlation between grinding parameters and the ceramic residual stresses was investigated. The research results show that the normal grinding force is the primary factor responsible for the generation of residual stress in grinding ceramic. The mechanical effect of the grains is to affect the magnitude, the depth of penetration and the gradient of the residual stresses.

The Characteristics of Surface Residual Stresses by Plane Grinding Invar and the Effects of Them on Structural Stability

2008 ◽  
Vol 53-54 ◽  
pp. 293-298
Author(s):  
Y.P. Qiao ◽  
Ren Ke Kang ◽  
Zhu Ji Jin ◽  
Dong Ming Guo
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Residual Stresses ◽  
Structure Stability ◽  
Tension Stress ◽  
Surface Residual Stress ◽  
Disk Model ◽  
Surface Residual Stresses ◽  
The Stability ◽  
Working Procedure

Invar 36 alloy is widely used in manufacturing instruments because of its minimal thermal expansion coefficient. As an important material for the components of precision or super-precision instruments, the process methods for Invar and the structure stability after its machining is necessary. In this paper, the residual stresses of the Invar samples after plane grinding were measured. The experimental results indicate that clear tension stress exists in the surface of Invar alloy along the grinding direction, while, on the cross direction, the states of surface residual stresses are complicated and affected by the parameters of grinding. A typical disk model has been calculated and analyzed by Finite Element Method (FEM), and the deformation caused by surface residual stress was presented. Finally, the effect of grinding as final working procedure on the stability of Invar structure was estimated.

Role of Quantitative NDE Techniques in Life Management of Gas Turbine Components

2006 ◽  
Author(s):  
Michael Gorelik ◽  
Waled T. Hassan ◽  
Harry Kington
Keyword(s):  
Residual Stress ◽  
Stress Gradient ◽  
Surface Residual Stress ◽  
Major Barrier ◽  
Near Surface ◽  
Life Management ◽  
Surface Residual Stresses ◽  
Engine Components ◽  
Nondestructive Measurements ◽  
Non Destructive

A number of earlier publications discussed the benefits of probabilistic analysis and probabilistic lifing in application to critical rotating engine components. One of the important variables in both probabilistic and deterministic lifing analysis is the level of residual stress in the component. Near surface residual stresses directly influence the fatigue life of critical engine rotating components. Depending on sign and magnitude a near surface residual stress gradient can either inhibit or accelerate fatigue initiation and crack propagation. A major barrier to introducing subsurface residual stress information into the life calculation process is the necessity to make accurate and reliable nondestructive measurements on as produced hardware. The paper reviews several NDE technologies that could be candidates for both production and in-service non-destructive residual stress measurements. The importance of having accurate residual stress information and its use in the probabilistic design and life management process is illustrated on several examples. A linkage with several ongoing industry R&D programs is discussed.

Investigation on the Workpiece Surface Residual Stress in High Efficiency Deep Grinding with Ultra High Wheel Speeds

2011 ◽  
Vol 487 ◽  
pp. 24-28
Author(s):  
Tan Jin ◽  
D.J. Stephenson ◽  
X.M. Sheng
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Contact Time ◽  
High Efficiency ◽  
Ground Surface ◽  
Grinding Process ◽  
Combined Effects ◽  
Surface Residual Stress ◽  
Workpiece Surface ◽  
Short Contact Time

The residual stress on the ground surface of workpiece in high efficiency deep grinding (HEDG) has been investigated. It has been found that the mechanism in forming the ground surface residual stress in HEDG is much different to that in the conventional shallow cut grinding process. It is not a thermally dominant event as in most of the shallow cut grinding mode; it is instead driven by the combined effects of both the thermal and mechanical loadings. The compressive plastic deformation near the workpiece surface during grinding and the short contact time in the HEDG regime, makes it possible to generate compressive surface stresses even when the surface temperatures are above 700-800°C.

Determination of surface residual stresses in carburised AISI 8620 steel by the magnetic Barkhausen noise method

2020 ◽  
Vol 62 (7) ◽  
pp. 416-421
Author(s):  
T Kaleli ◽  
C Hakan Gür
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Fatigue Behaviour ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Surface Residual Stress ◽  
Technical Requirements ◽  
Surface Residual Stresses

Management of the residual stress state is vital for the design and production stages of carburised components in order to satisfy the technical requirements related to performance, fatigue behaviour and useful lifetime. This enforces the use of practical, reliable and time- and cost-effective stress measurement methods by manufacturers. This study aims to investigate the efficiency of the magnetic Barkhausen noise (MBN) method in rapid non-destructive determination of surface residual stresses in carburised steels. A series of AISI 8620 steel specimens with different residual stress states was prepared by altering the carburising and subsequent tempering parameters. The specimens were characterised through scanning electron microscopy (SEM) investigations and hardness measurements, and the surface residual stresses were determined using both the MBN and X-ray diffraction (XRD) methods. The results show that a good correlation exists between surface residual stress and the parameters derived from the MBN signals.

Statistical Analysis of Surface and Sub-Surface Residual Stress Fields in Retrieved Alumina Femoral Heads after Long-Term Implantation

2006 ◽  
Vol 309-311 ◽  
pp. 1251-1256
Author(s):  
Toshiyuki Tateiwa ◽  
Kengo Yamamoto ◽  
T. Kumakura ◽  
F. Variola ◽  
Giuseppe Pezzotti ◽  
...  
Keyword(s):  
Residual Stress ◽  
Femoral Head ◽  
Microscopic Analysis ◽  
Ceramic Materials ◽  
Joint Surface ◽  
Spectroscopic Techniques ◽  
Surface Residual Stress ◽  
Testing Procedures ◽  
Femoral Heads

The surface of retrieved alumina (Al2O3) femoral heads was investigated by piezo-spectroscopic techniques based on confocal photo-stimulated fluorescence. The micrometric spatial resolution of the laser beam impinging on the investigated joint surface (typically about 1 $m in lateral resolution) enabled us estimating patterns and magnitude of residual stress in extremely narrow zones, at least comparable with the grain size of the material. According to a statistical collection of data on a microscopic level, it was possible to assess the retrieved femoral heads in-toto, thus extending the microscopic analysis to the entire surface of the joint. A stress field was found, which mainly arose from loading history, and displacements acting on the femoral head during its lifetime. Residual stress data enabled us to draw interesting conclusions about the role of the material microstructure and the peculiar kinetic mechanisms involved with the use of the joint. Spectroscopic techniques, which are complementary to in vitro testing procedures and theoretical stress analyses based on finite-element methods, can be very useful in improving the design of the femoral head and in optimizing the microstructural characteristics of the ceramic materials employed.

Analysis of the Surface Residual Stress in Grinding Aermet100

2011 ◽  
Vol 704-705 ◽  
pp. 318-324
Author(s):  
Y.Q. Xu ◽  
T. Zhang ◽  
Y.M. Bai
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Thermal Expansion ◽  
Tensile Stress ◽  
Heat Source ◽  
Residual Stresses ◽  
Surface Grinding ◽  
Grinding Process ◽  
Surface Residual Stress ◽  
Abrasive Grains

Grinding induces residual stresses, which can play an important role on the fatigue of the component. In general, residual stresses in a ground surface are primarily generated due to three effects: thermal expansion and contraction during grinding, plastic deformation caused by the abrasive grains of the wheel and phase transformations due to high grinding temperature. It was found that thermal expansion and plastic deformation in the grinding process were the major causes of residual stresses. In this paper, an analysis model for the calculation of residual stresses induced by a surface grinding process on an ultrahigh-strength steel (Aermet100) workpiece is presented. Firstly, the stress distribution induces by thermal expansion was obtained base on the transient heat conduction equation and the thermal properties of Aermet100. All the calculations were based on the moving heat source solution which was modeled as a uniformly distributed, 2D heat source moving across the surface of a half-space, found in Carslaw and Jaeger. The results show that the near surface residual stress is predominantly tensile and that the magnitude of this stress increases with increasing heat flux values. Secondly, the plastic deformation caused by the abrasive grains of the wheel was simulated base on the grain-workpiece interaction. The chip formation process and the material removal mechanisms can be examined using the micro-scale approach. The results show that the residual stress induced by the grinding force itself is generally compressive which is smaller than the residual tensile stress induced by thermal stress. Therefore, the residual stress brought about by grinding operation is generally a tensile stress. This paper offers an insight into the mechanism understanding of thermal and mechanical residual stresses induced by surface grinding. Key words: grinding, residual stress, grain

Research on Grinding Residual Stresses on the Surface of Nanostructured Ceramic Coatings

2013 ◽  
Vol 709 ◽  
pp. 131-134
Author(s):  
Wei Xiang Liu ◽  
Zhong Yu Zhou
Keyword(s):  
Residual Stress ◽  
Corrosion Resistance ◽  
Fatigue Strength ◽  
Service Life ◽  
Residual Stresses ◽  
Ceramic Coatings ◽  
Grinding Process ◽  
Abrasive Wheel ◽  
Nanostructured Ceramic

Residual stress produced on the surface of nanostructured ceramic coatings when they were grinded by diamond superhard abrasive wheel, these residual stresses affected directly the fracture strength, fatigue strength and corrosion resistance of the ceramic parts, they affected the surface quality of machined ceramic parts, and thus they affected the working reliability and the service life of ceramic parts. The tests show that the distribution of residual stress is directional, the residual compressive stress can make the hardness of the material increase, they can reduce the wear rate of the material, for the tested specimen, grinding surface whole residual stress σ is the sum up original residual stress σ0(existed in the part’s surface ) and grinding residual stress Δσ (formed by grinding process.), σ=σ0+ Δσ.

Micro-slotting technique for reliable measurement of sub-surface residual stress in Ti-6Al-4V

2018 ◽  
Vol 53 (6) ◽  
pp. 389-399 ◽  
Author(s):  
Elizabeth Burns ◽  
Joseph Newkirk ◽  
James Castle
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Image Correlation ◽  
X Ray Diffraction ◽  
Surface Residual Stress ◽  
Near Surface ◽  
X Ray ◽  
Measurement Volume ◽  
Surface Residual Stresses

Micro-slotting, a relaxation residual stress measurement technique, has recently been shown to be an effective method for measuring local residual stresses in a variety of materials. The micro-slotting method relies on a scanning electron microscope–focused ion beam system for milling and imaging, digital image correlation software to track displacements due to residual stress relaxation after milling, and finite element analysis for displacement–stress correlation and calculation of the original stress state in the imaged region. The high spatial resolution of the micro-slotting method makes it a promising technique for obtaining near-surface residual stress data in Ti-6Al-4V components for input into fatigue life models and crack growth simulations. However, use of the micro-slotting method on this alloy has yet to be evaluated against more established measurement techniques. In this study, spatially resolved sub-surface residual stress measurements were obtained on shot peened and low-stress surface-machined Ti-6Al-4V planar coupons using the micro-slotting method and were compared to measurements obtained using the conventional X-ray diffraction depth profiling technique. The sub-surface measurements were in good agreement for the shot peened sample. Observed differences in the measured near-surface residual stresses on the surface-machined sample were attributed to the larger measurement volume of the X-ray diffraction method, suggesting that the micron-sized measurement volume of the micro-slotting method may be more suitable for capturing shallow stress profiles and steep stress gradients. Prior to performing the micro-slotting measurements, finite element modeled displacements were used to verify the measurement procedure and to address uncertainties in the milled slot geometries. The results of this study demonstrated the validity of the micro-slotting procedure and established the technique as a reliable method for measuring sub-surface residual stresses in Ti-6Al-4V.

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