WC-Co Tool Failure Analysis and the Grinding Effect Study

2010 ◽  
Vol 139-141 ◽  
pp. 269-273 ◽  
Author(s):  
Xiu Xu Zhao
Keyword(s):  
Residual Stress ◽  
Effect Study ◽  
Work Piece ◽  
Grinding Process ◽  
X Ray Diffraction ◽  
Machining Processes ◽  
Tool Failure ◽  
Micro Cracks ◽  
Comparison Results ◽  
Grinding Conditions

Grinding is one of the important machining processes for the WC-Co carbide product. Different grinding strategies will have different impact on the work piece material. This study focuses on the WC-Co carbide grinding process, and the effect of grinding condition on the WC-Co carbide microstructure, figures out the relationship between different grinding strategies and material microstructure which relate to the WC-Co carbide tool failure. A specific microstructure analysis with Scanning Electric Microscope (SEM) will be presented based on a series of grinding experiments. The residual stress that generated in the grinding process will also be discussed based on the X-Ray Diffraction (XRD) measurements. It has been found that micro cracks are generated at certain grinding conditions with certain level. The residual stress which generated in the grinding process can be calculated by the d-spacing shift, and the comparison results show micro-cracks level is corresponding with the peaks shift in XRD test.

Fatigue Life Variance Prediction Incorporating Residual Stress Scatter Induced by Super-Finishing Grinding Process

2009 ◽  
Vol 416 ◽  
pp. 45-50
Author(s):  
Guang Hui Lu ◽  
Xue Ping Zhang ◽  
Er Wei Gao
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Diffraction Method ◽  
Machining Process ◽  
Stress Distributions ◽  
X Ray Diffraction ◽  
Machining Processes ◽  
Surface Residual Stress ◽  
Bearing Rings ◽  
The Impact

It is well known that there is a lager deviation in the fatigue life of machined components even under nominally identical loading conditions. Understanding and controlling fatigue life variance are essential to enhance reliability. However, few research focus on the impact of machining processes on the fatigue life variance of machined components. In this study, surface residual stress distributions of bearing rings randomly selected from a production line by super-finishing grinding, are measured by X-ray diffraction method in cutting and feed direction, and its scatter is analyzed by statistical tools. Based on the variance prediction theories, build a simplified fatigue life variance prediction model incorporating the resultant residual stresses scatter induced by machining process. Based on the Basquin equation, the model is validated by experimental data published in literature. The predicted fatigue life agrees well with the experimental average fatigue life. Statistical analysis shows that the predicted variances of fatigue life are equal to those estimated from experimental fatigue life.

Effect of Laser Peening on Residual Stress and Micro-Hardness of TC4 Titanium Alloy

2013 ◽  
Vol 341-342 ◽  
pp. 246-250
Author(s):  
Hong Chao Qiao ◽  
Ji Bin Zhao ◽  
Yi Xiang Zhao ◽  
Lun Li
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Layer Thickness ◽  
Pulse Energy ◽  
Work Piece ◽  
Laser Peening ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
Tc4 Titanium Alloy

Laser peening offers potential advantages over conventional peen technologies in terms of the depth of the residual stresses that can be induced, and improvements in surface micro-hardness. The present study was undertaken to understand the effect of laser penning on the properties of titanium alloy, a TC4 titanium alloy work-piece was processed with ND: YAG laser with the wavelength of 1064 nm, pulse energy of 0-10J and pulse width of 12ns, and micro-hardness and residual stress for different laser peening parameters were examined and analyzed by micro-hardness tester and X-ray diffraction. Results are presented and discussed of the residual stress profiles and the micro-hardness profiles, The experimental results show that the satisfying laser peening appearance can be achieved when the pulse energy was 6J, water tamping layer thickness was 1.8mm and ablative layer thickness was 100μm, surface micro-hardness increased by up to 33% and the compressive residual stress on the surface of laser shocked area reached up to-327.8MPa, laser peening improved hardness and residual stress of titanium alloy significantly. The experiment results show that the effect of laser peening was evidently.

Effect of Substrate Temperature on Crystal Orientation and Residual Stress in RF Sputtered Gallium Nitride Films

2005 ◽  
Vol 490-491 ◽  
pp. 613-618 ◽  
Author(s):  
Kazuya Kusaka ◽  
Hanabusa Takao ◽  
Kikuo Tominaga ◽  
Noriyoshi Yamauchi
Keyword(s):  
Residual Stress ◽  
Gallium Nitride ◽  
Crystal Orientation ◽  
Substrate Surface ◽  
Rf Sputtering ◽  
Input Power ◽  
X Ray Diffraction ◽  
Micro Cracks ◽  
Increasing Temperature ◽  
Sputtering System

The crystal orientation and residual stress in gallium nitride (GaN) films deposited on a single-crystal (0001) sapphire substrate using a new sputtering system are examined through x-ray diffraction measurements as part of a study of low-temperature sputtering techniques for GaN. The new rf sputtering system has an isolated deposition chamber to prevent contamination with impurities, and is expected to produce high-purity nitride films. GaN films are deposited at various substrate temperatures and constant gas pressure and input power. This new system is found to produce GaN films with good crystal orientation, with the c-axes of GaN crystals oriented normal to the substrate surface. The crystal size of films deposited at high temperature is larger than that deposited at low Ts. All films except that deposited at 700oC exhibit compressive residual stress, and this residual stress is found to decrease with increasing temperature. Finally, the film deposited at 700 oC was tinged with white, and the surface contained numerous micro-cracks.

Investigation into the Grindability and Surface Integrity of the Nickel Base Superalloy Using Liquid Nitrogen Jet Grinding

2010 ◽  
Vol 426-427 ◽  
pp. 49-54 ◽  
Author(s):  
Chang He Li ◽  
Ya Li Hou ◽  
Yu Cheng Ding
Keyword(s):  
Surface Integrity ◽  
High Speed ◽  
Ground Surface ◽  
Cryogenic Cooling ◽  
Cutting Fluid ◽  
Nickel Base Superalloy ◽  
Grinding Process ◽  
Machining Processes ◽  
Grinding Conditions ◽  
Nickel Base

Grinding processes are mainly technique employed widely as a finishing process in a variety of materials, such as metals, hardness and brittleness and ductile materials machining to achieve good dimensional and form accuracy of the product with acceptable surface integrity. However, grinding is associated with high specific energy requirements which may be an order higher than that required in other conventional machining processes such as turning, planning, milling etc. Therefore, in grinding process, high grinding zone temperature may lead to thermal damage to the work surface, induces micro-cracks and tensile residual stresses at the ground surfaces, which deteriorate surface quality and integrality of the ground surface. Therefore, grinding fluids are applied in different forms to control such high temperature, but they are ineffective, especially under high speed grinding conditions where the energy of the fluid is not sufficient to penetrate the boundary layer of air surrounding the wheel. Moreover, the conventional flood supply system demands more resources for operation, maintenance, and disposal, and results in higher environmental and health problems. Therefore, there are critical needs to reduce the use of cutting fluid in grinding process, and cryogenic cooling grinding is a promising solution. The work presented in this paper aims at evaluating the grind ability and surface integrity of the nickel base super alloy resulting from the application of cryogenic cooling.

High-Precision Determination of Residual Stress of As-Sprayed and Ground WC-10Co-4Cr Coating Using Optimized XRD-sin2ψ Technique

2017 ◽  
Vol 748 ◽  
pp. 381-385 ◽  
Author(s):  
Maedeh Sadat Zoei ◽  
Mohamad Hosein Sadeghi ◽  
Mehdi Salehi
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
High Surface ◽  
Hard Coatings ◽  
Grinding Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbide Coatings ◽  
Positioning Method ◽  
Coated Surface

Thermally sprayed tungsten carbide-based coatings deposited by High Velocity Oxygen Fuel (HVOF) has been widely developed for its high corrosion and wear resistance. The finishing of the coated surface by grinding process is essential because of the high surface roughness of carbide coatings. Residual stresses existing in most hard coatings have significant influence on the adhesion, mechanical properties and tribological performance. The present study investigated the effect of grinding process on the residual stress of WC-10Co-4Cr coating by HVOF. The residual stress of coating was measured by the X-ray diffraction (XRD) technique using sin2ψ method. In addition, the effect of diffraction peak positioning method on the accuracy of residual stress of WC-10Co-4Cr coating was determined in the XRD technique. Four peak positioning methods and their effects on the accuracy of X-ray diffraction (XRD) residual stress measurement are considered. The results showed that the compressive residual stress of the WC-10Co-4Cr coating increase after grinding process. The parabolic method was selected for the peak positioning to measure the precise residual stress of HVOF-deposited WC-10Co-4Cr coating.

Grinding Affect the Service Life of Mould Research

2013 ◽  
Vol 850-851 ◽  
pp. 225-228
Author(s):  
Fang He
Keyword(s):  
Residual Stress ◽  
Service Life ◽  
Cavity Surface ◽  
Grinding Process ◽  
Processing Quality ◽  
Micro Cracks ◽  
Close Relationship ◽  
Mould Cavity ◽  
Manufacturing Time

In the process of modern mould manufacturing, grinding work still account for 25% ~ 45% of the total manufacturing time mould. Mould manufacturing quality of the finished product is closely related to the precision of mould manufacturing, particularly with the mould cavity surface accuracy and surface roughness has a close relationship. In the manufacturing of mould to make grinding micro cracks and residual stress is reduced to a minimum, full attention, grinding process in order to improve the service life of mould. So research to improve grinding processing quality, improve the service life of the mold, to extend the time of service, has the positive significance

Effect of Laser Peening on Residual Stress and Micro-Hardness of TC4 Titanium Alloy

2013 ◽  
Vol 710 ◽  
pp. 208-212
Author(s):  
Hong Chao Qiao ◽  
Ji Bin Zhao ◽  
Yi Xiang Zhao ◽  
Lun Li
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Layer Thickness ◽  
Pulse Energy ◽  
Work Piece ◽  
Laser Peening ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
Tc4 Titanium Alloy

Laser peening offers potential advantages over conventional peen technologies in terms of the depth of the residual stresses that can be induced, and improvements in surface micro-hardness. The present study was undertaken to understand the effect of laser penning on the properties of titanium alloy, a TC4 titanium alloy work-piece was processed with ND: YAG laser with the wavelength of 1064 nm, pulse energy of 0-10J and pulse width of 12ns, and micro-hardness and residual stress for different laser peening parameters were examined and analyzed by micro-hardness tester and X-ray diffraction. Results are presented and discussed of the residual stress profiles and the micro-hardness profiles, The experimental results show that the satisfying laser peening appearance can be achieved when the pulse energy was 6J, water tamping layer thickness was 1.8mm and ablative layer thickness was 100μm, surface micro-hardness increased by up to 33% and the compressive residual stress on the surface of laser shocked area reached up to-327.8MPa, laser peening improved hardness and residual stress of titanium alloy significantly. The experiment results show that the effect of laser peening was evidently.

scholarly journals Optimization of Process Parameter of Surface Grinding Process of Autenitic Stainless Steel (AISI 304) BY Taguchi Method

2019 ◽  
pp. 72-76
Author(s):  
M. A. Deore ◽  
R. S Shelke
Keyword(s):  
Taguchi Method ◽  
Feed Rate ◽  
Metal Removal ◽  
Removal Rate ◽  
Surface Grinding ◽  
Machining Process ◽  
Depth Of Cut ◽  
Work Piece ◽  
Grinding Process ◽  
Machining Processes

The manufacturing process of surface grinding has been established in the mass production of slim, rotationally symmetrical components. Due to the complex set-up, which results from the large sensitivity of this grinding process to a multiplicity of geometrical, kinematical and dynamical influence parameters, surface grinding is rarely applied within limited-lot production. The substantial characteristics of this grinding process are the simultaneous guidance and machining of the work piece on its periphery. Surface grinding is an essential process for final machining of components requiring smooth surfaces and precise tolerances. As compared with other machining processes, grinding is costly operation that should be utilized under optimal conditions. Although widely used in industry, grinding remains perhaps the least understood of all machining processes. The proposed work takes the following input processes parameters namely Work speed, feed rate and depth of cut. The main objective of this work is to predict the grinding behavior and achieve optimal operating processes parameters. a software package may be utilized which integrates these various models to simulate what happens during surface grinding processes. predictions from this simulation will be further analyzed by calibration with actual data. It involves several variables such as depth of cut, work speed, feed rate, chemical composition of work piece, etc. The main objective in any machining process is to maximize the Metal Removal Rate (MRR) and to minimize the surface roughness (Ra). In order to optimize these values Taguchi method, ANOVA and regression analysis is used.

scholarly journals Effect of Cold Pressing and Aging on Reduction and Evolution of Quenched Residual Stress for Al-Zn-Mg-Cu T-Type Rib

2021 ◽  
Vol 11 (12) ◽  
pp. 5439
Author(s):  
Yaoqiong Liu ◽  
Tao Zhang ◽  
Hai Gong ◽  
Yunxin Wu
Keyword(s):  
Residual Stress ◽  
Stress Reduction ◽  
Numerical Models ◽  
Maximum Tensile Stress ◽  
Contour Method ◽  
X Ray Diffraction ◽  
Machining Processes ◽  
Heterogeneous Distribution ◽  
Cold Pressing ◽  
X Ray

The preparation of the Al-Zn-Mg-Cu T-type rib consisted of forging, quenching, cold pressing, aging and the final machining processes, and the evolution of residual stress played a significant role in its properties and accuracy. Numerical models were established to investigate the evolution and distribution of residual stress for the T-type rib during the quenching and cold pressing processes. The results showed that the distribution of residual stress at the stiffened area is asymmetrical, which is different from the symmetrical distribution at the smooth area. The cold pressing is beneficial for the reduction of residual stress. The stepwise cold pressing resulted in the heterogeneous distribution of residual stress at the stiffened area and the overlap region. Three comparative T-type ribs were conducted, and their residual stresses were measured using X-ray diffraction and the contour method. A stress reduction of 50% can be obtained at the surfaces of the T-type rib through cold pressing followed by the aging process. The reduction of the maximum tensile stress at the stiffened area of the T-type rib was 42% and 50% for the cold pressing and aging, respectively, which increased to 54% and 60% at the smooth area. The mechanism of the stress reduction during the cold pressing and the aging processes was discussed.

Temperature Dependence of Residual Stress Gradients in Shot-Peened Steel Coated with CrN

2008 ◽  
Vol 571-572 ◽  
pp. 101-106 ◽  
Author(s):  
Klaus J. Martinschitz ◽  
C. Kirchlechner ◽  
R. Daniel ◽  
G. Maier ◽  
C. Mitterer ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Temperature Dependence ◽  
X Ray Diffraction ◽  
Stress Gradients ◽  
Coated Tools ◽  
Micro Cracks ◽  
Depth Gradients

A temperature behaviour of residual stresses in shot-peened steel coated with 3m CrN is characterized using in-situ energy dispersive synchrotron X-ray diffraction performed in the temperature range of 25-800°C. The samples are thermally cycled and the development of volumeaveraged residual stresses in the coating and residual stress depth gradients in the steel is characterized. The results reveal complex changes of stresses in CrN and in the substrate. The annealing results in the removal of stress gradients in the steel which starts at the temperature of about 600°C. After cooling down, there are no stresses detected in the steel. The temperature dependence of stresses in CrN is very complex and indicates the presence of phenomena like an annealing of intrinsic stresses about the deposition temperature of 350°C, a formation and a closing of micro-cracks in the tensile region and finally a stress relaxation of approximately 500 MPa after the cooling down. The presented approach allows a complex characterization of thermo-mechanical processes in coating-substrate composites and opens the possibility to understand phenomena related to the thermal fatigue of coated tools.

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