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.

Characterization of the Residual Stresses and Strength of Ceramic-Metal Braze Joints

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Matteo Galli ◽  
John Botsis ◽  
Jolanta Janczak-Rusch ◽  
Gerd Maier ◽  
Udo Welzel
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Finite Element Models ◽  
Plastic Response ◽  
X Ray Diffraction ◽  
Elastoplastic Properties ◽  
Bend Tests ◽  
Point Bend ◽  
Good Agreement

Residual stress relief in ceramic-metal joints produced by active brazing depends primarily on the plastic response of the filler metal. A procedure for the production and mechanical characterization of bulk active filler alloy specimens is developed. In parallel ceramic-metal joints are produced and tested. Residual stresses are measured by X-ray diffraction while the joint strength is assessed by four-point bend tests. The obtained elastoplastic properties of the filler are introduced into finite element models to predict the residual stresses in the joints and their behavior in bending. The results of the simulations show good agreement both with the residual stress measurements and with the results of four-point bend tests.

Sample tilt-free characterization of residual stress gradients in thin coatings using an in-plane arm-equipped laboratory X-ray diffractometer

2014 ◽  
Vol 47 (6) ◽  
pp. 1931-1938 ◽  
Author(s):  
Andrei Benediktovitch ◽  
Tatjana Ulyanenkova ◽  
Jozef Keckes ◽  
Alex Ulyanenkov
Keyword(s):  
Residual Stress ◽  
Stress Gradient ◽  
Complex Stress ◽  
Depth Range ◽  
Experimental Conditions ◽  
X Ray ◽  
Stress Gradients ◽  
Five Axis

A methodology is presented to characterize residual stress gradients using the sin2ψ technique at constant penetration depths without the use of sample χ tilting. The experiments were performed using a laboratory five-axis X-ray diffractometer equipped with an in-plane arm by scanning several reflections in order to enlarge the penetration depth range. The proposed approach, demonstrated on a blasted 11.5 µm-thick TiN coating on a WC–Co substrate, opens the possibility to perform a complex stress gradient characterization in laboratory conditions where the sample χ tilting can deteriorate the sample properties or experimental conditions, like duringin situhigh-temperature studies.

Characterization of Bolt Hole Residual Stresses for Assessing Structural Behavior of Truck Frame Rails

2011 ◽  
Vol 418-420 ◽  
pp. 1124-1131
Author(s):  
K. Chinnaraj ◽  
M. Sathya Prasad ◽  
C. Lakshmana Rao
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Initial Conditions ◽  
Fatigue Cracks ◽  
Structural Behavior ◽  
X Ray Diffraction ◽  
Water Jet Cutting ◽  
Large Numbers ◽  
Bolt Holes

Chassis frame rails in a truck are load bearing structural members that integrate vehicle power train with superstructure to form a complete vehicle. Large numbers of bolt holes that are cut into these frame side members act as joineries and points of attachments for various sub systems of the truck. While bolt holes are unavoidable due to its primary functional importance, the near hole residual stresses remaining from hole cutting operations may play a significant role in deciding the life of frame rail sections as they lead to early initiation of fatigue cracks around bolt hole surface. In order to assess the extent of plastic deformation and resulting residual stress pattern in near hole areas of bolt holes, experimental investigation through microstructure analysis, micro-hardness and X-ray diffraction measurements has been taken up. The hole cutting operations considered for this exercise are drilling, punching, laser cutting and water jet cutting used to cut holes on truck frame rail sections. Apart from this, an assessment of shot-peened hole surface was also taken up to understand the effect of shot-peening on structural behavior of frame rail bolt hole sections. The experimentally measured near hole residual stress profiles can be considered as initial conditions for further numerical analysis to study the influence of bolt hole residual stresses on fatigue life of frame rail sections.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Revision and extension of the standard laboratory technique for X-ray diffraction measurement of residual stress gradients

2007 ◽  
Vol 40 (4) ◽  
pp. 675-683 ◽  
Author(s):  
Cristy L. Azanza Ricardo ◽  
Mirco D'Incau ◽  
Paolo Scardi
Keyword(s):  
Residual Stress ◽  
Hole Drilling ◽  
Al Alloy ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Surface Residual Stress ◽  
X Ray ◽  
Stress Gradients ◽  
Layer Removal ◽  
Removal Technique

A new procedure is proposed to determine sub-surface residual stress gradients by laboratory X-ray diffraction measurements at different depths using a chemical layer-removal technique. The standard correction algorithm for stress relaxation due to layer removal is improved by including corrections for X-ray absorption, and by the addition of constraints imposed by the mechanical equilibrium conditions. Besides correcting the data,i.e.providing more reliable through-thickness residual stress trends, the proposed procedure also provides an elastically compatible and plausible estimate of the residual stress inside the component, well beyond the measured region. The application of the model is illustrated for a set of Al-alloy components shot-peened at different Almen intensities. Results are compared with those given by `blind hole drilling', which is an independent and partly destructive method.

Synthesis and Characterization of the PANI/ITO Conducting Nanocomposites

2010 ◽  
Vol 663-665 ◽  
pp. 542-545 ◽  
Author(s):  
Bing Jie Zhu ◽  
Xin Wei Wang ◽  
Mei Fang Zhu ◽  
Qing Hong Zhang ◽  
Yao Gang Li ◽  
...  
Keyword(s):  
Doping Concentration ◽  
In Situ Polymerization ◽  
Synthesis And Characterization ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Conductivity ◽  
Scanning Electron

The PANI/ITO conducting nanocomposites have been synthesized by in-situ polymerization. The obtained nanocomposites were characterized by X-ray diffraction pattern, scanning electron microscopy and Fourier transform infrared. Electrical conductivity measurements on the samples pressed into pellets showed that the maximum conductivity attained 2.0 ± 0.05 S/cm for PANI/ITO nanocomposites, at ITO doping concentration of 10 wt%. The results of the present work may provide a simple, rapid and efficient approach for preparing PANI/ITO nanocomposites.

scholarly journals Characterization of the Interface Between the Bulk Glass Forming Alloy Zr41Ti14Cu12Ni10Be23 with Pure Metals and Ceramics

2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson
Keyword(s):  
Sessile Drop ◽  
Bulk Glass ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Processing Times ◽  
Thermal Stability Of

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.

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.

Synthesis and Characterization of Tetraphenylphosphonium Tetraazidoborate

2002 ◽  
Vol 57 (6) ◽  
pp. 621-624 ◽  
Author(s):  
Wolfgang Fraenk ◽  
Heinrich Nöth ◽  
Thomas M. Klapötke ◽  
Max Suter
Keyword(s):  
Single Crystal ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray

AbstractTetraphenylphosphonium tetraazidoborate, [P(C6H5)4][B(N3)4], was obtained from B(N3)3 - in situ prepared from BH3 · O(C2H5)2 and HN3 - and [P(C6H5)4][N3]. Recrystallization from an acetonitrile / hexane mixture yielded colorless crystals in 60% yield. The molecular structurewas determined by single crystal X-ray diffraction and the [B(N3)4]- anionwas shown to possess S4 symmetry.

scholarly journals Crystalline Swelling Process of Mg-Exchanged Montmorillonite: Effect of External Environmental Solicitation

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Marwa Ammar ◽  
Walid Oueslati
Keyword(s):  
Theoretical Models ◽  
Retention Mechanism ◽  
X Ray Diffraction ◽  
Interlayer Water ◽  
Hydration Properties ◽  
Crystalline Swelling ◽  
Low Charge ◽  
Interlayer Water Molecule

This work reports characterization of the possible effects that might distress the hydration properties of Mg-exchanged low-charge montmorillonite (SWy-2) when it undergoes external environmental solicitation. This perturbation was created by an alteration of relative humidity rates (i.e., RH%) over two hydration-dehydration cycles with different sequence orientations. Structural characterization is mainly based on the X-ray diffraction (XRD) profile-modeling approach achieved by comparing the “in situ” obtained experimental 00l reflections with other ones calculated from theoretical models. This method allows assessing the evolution of the interlayer water retention mechanism and the progress of diverse hydration state’s contributions versus external strain. Obtained results prove that the hydration behavior of the studied materials is strongly dependent on the RH sequence orientation which varied over cycles. The interlayer organization of Mg-exchanged montmorillonite (i.e., SWy-2-Mg) is characterized by a heterogeneous hydration behavior, which is systematically observed at different stages of both cycles. By comparing the interlayer water process evolution of Mg-exchanged montmorillonite with the observed SWy-2-Ni sample hydration behaviors, a same hysteresis thickness characterized by obvious fluctuations of interlayer water molecule abundances is observed. Nevertheless, in the case of Hg and Ba-saturated montmorillonite, the retention water process versus the applied cycles was steadier comparing with Mg ions.

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