Efficient Super-Smooth Finishing Characteristics of SiC Materials through the Use of Fine-Grinding

2009 ◽  
Vol 404 ◽  
pp. 137-141 ◽  
Author(s):  
H. Kasuga ◽  
Hitoshi Ohmori ◽  
Wei Min Lin ◽  
Y. Watanabe ◽  
T. Mishima ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Surface Analysis ◽  
Grinding Process ◽  
Structural Components ◽  
X Ray ◽  
Fine Grinding ◽  
Elid Grinding ◽  
Grinding Method ◽  
Wide Range ◽  
Experimental Parameters

Silicon carbide (SiC) materials have increasingly been needed in the wide range of industries, such as for structural components, automobile parts, space telescope, X-ray mirror, and next-generation semiconductors. However, SiC materials have difficulties in super-smooth finishing because of their hard and brittle characteristics. The authors have been investigating appropriate conditions on their finishing by fine-grinding with the unique grinding process called ELID (Electrolytic In-process Dressing) grinding method. The ELID grinding method has a stable grinding ability, so very detailed characteristics of their material-remove mechanisms were to be investigated. Surface analysis of each material has been discussed through the ELID, and this study proposes good finishing conditions for SiC. In this paper, the advantages of the applied fine-grinding are shown, and unique features on grinding characteristics of SiC through various grinding experimental parameters are described.

Preparation of Silicon Carbide Nanowires and Nanochains Using Chemical Vapor Deposition Method

2016 ◽  
Vol 697 ◽  
pp. 841-845 ◽  
Author(s):  
Jia Xing Chang ◽  
Rong Zheng Liu ◽  
Ma Lin Liu ◽  
You Lin Shao ◽  
Bing Liu
Keyword(s):  
Silicon Carbide ◽  
Chemical Vapor Deposition ◽  
Electron Microscope ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Raw Material ◽  
Chemical Vapor Deposition Method ◽  
Deposition Method ◽  
X Ray ◽  
Wide Range

Silicon carbide nanowires have been extensively studied because of their unique physical and chemical properties. They can be applied in high temperature, high frequency, high power, and corrosive environments, and have a wide range of applications in electronics, chemical industry, energy and other fields. In this paper, SiC nanowires with high output were synthesized by chemical vapor deposition method using methyltrichlorosilane as raw material. The influences of the catalyst and temperature were studied. SiC nanochains were also obtained by adding Al2O3 powder under appropriate temperature controlled strategy. These two kinds of one-dimensional SiC nanomaterials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS) and transmission electron microscope (TEM) methods.

F-0506 Ultraprecision ELID Grinding Method of the X-ray Mirrors

2001 ◽  
Vol III.01.1 (0) ◽  
pp. 277-278
Author(s):  
Weimin LIN ◽  
Hitoshi OHMORI ◽  
Yutaka YAMAGATA ◽  
Sei MORIYASU ◽  
Yoshiyuki UENO ◽  
...  
Keyword(s):  
X Ray ◽  
Elid Grinding ◽  
Grinding Method

scholarly journals A phase-retrieval toolbox for X-ray holography and tomography

2020 ◽  
Vol 27 (3) ◽  
pp. 852-859 ◽  
Author(s):  
Leon M. Lohse ◽  
Anna-Lena Robisch ◽  
Mareike Töpperwien ◽  
Simon Maretzke ◽  
Martin Krenkel ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Phase Retrieval ◽  
Performance Test ◽  
Limiting Factor ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging ◽  
Wide Range ◽  
Experimental Parameters ◽  
And Performance

Propagation-based phase-contrast X-ray imaging is by now a well established imaging technique, which – as a full-field technique – is particularly useful for tomography applications. Since it can be implemented with synchrotron radiation and at laboratory micro-focus sources, it covers a wide range of applications. A limiting factor in its development has been the phase-retrieval step, which was often performed using methods with a limited regime of applicability, typically based on linearization. In this work, a much larger set of algorithms, which covers a wide range of cases (experimental parameters, objects and constraints), is compiled into a single toolbox – the HoloTomoToolbox – which is made publicly available. Importantly, the unified structure of the implemented phase-retrieval functions facilitates their use and performance test on different experimental data.

Growth and Characterization of a Combinatorial Array of Mixed-Phase Magnesium-Aluminum Thin-Film Alloys

2007 ◽  
Vol 1056 ◽  
Author(s):  
Charles Olk ◽  
Daad B. Haddad
Keyword(s):  
Elevated Temperatures ◽  
Mixed Phase ◽  
Al Alloy ◽  
Structural Components ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mg17al12 Phase ◽  
Wide Range ◽  
Compositional Characterization

ABSTRACTCombinatorial gradient-controlled sputter deposition has been employed to produce a library of 100 separate thin films with a wide range of Mg-Al alloy compositions. We have successfully isolated the â (Mg17Al12) phase in polycrystalline films for investigation. The presence of the â phase has been found to be desirable for increasing corrosion resistance; however, in structural components under tensile loading and/or at elevated temperatures, the â phase precipitates undergo coarsening which induces poor creep behavior in several common alloys. We have also synthesized amorphous Mg-Al and mixed-phase compositions as identified by X-ray diffraction measurements. Details of the growth procedure as well as structural and compositional characterization are presented.

ELID Grinding Characteristics and Surface Analysis for Micro Fabrication of Advanced Ceramics

2007 ◽  
Vol 339 ◽  
pp. 483-489 ◽  
Author(s):  
Kazutoshi Katahira ◽  
Hitoshi Ohmori
Keyword(s):  
Surface Hardness ◽  
Ground Surface ◽  
Ceramic Materials ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Spherical Lens ◽  
Elid Grinding ◽  
Grinding Method ◽  
Centerless Grinding ◽  
Ground Surface Roughness

The present paper describes the highly efficient and precise ELID grinding method and presents a discussion on the ELID grinding process and the grinding characteristics of several kinds of ceramic materials. The following conclusions are obtained; (1) Good ground surface roughness and accuracy are achieved using the #4000 metal-bonded grinding wheel in through-feed centerless grinding for ZrO2 optical fiber ferrules. (2) Efficient and precise grinding of spherical lens molds with cup wheels using the ELID CG-grinding process was proposed and tested in the present study. (3) The ELID grinding method can be used to fabricate machined surfaces exhibiting desirable characteristics for hard AlN ceramics. The ELID ground AlN demonstrated a surface hardness and sliding characteristics that were superior to those of the polished series. These advantages may be attributable to the diffusion phenomenon of the oxygen element produced by the ELID grinding.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Evaluation of the accuracy indicators in determination of the coating thickness by crater grinding method

2020 ◽  
Vol 86 (7) ◽  
pp. 39-44
Author(s):  
K. V. Gogolinsky ◽  
A. E. Ivkin ◽  
V. V. Alekhnovich ◽  
A. Yu. Vasiliev ◽  
A. E. Tyurnina ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Functional Dependence ◽  
Measurement Procedure ◽  
Metrological Certification ◽  
Measuring Instruments ◽  
Properties Of Coatings ◽  
Special Equipment ◽  
Grinding Method ◽  
Accuracy Of Measurements ◽  
Wide Range

Thickness is one of the key indicators characterizing the quality and functional properties of coatings. Various indirect methods (electromagnetic, radiation, optical) most often used in practice to measure thickness are based on the functional dependence of a particular physical parameter of the system «base – coating» on the coating thickness. The sensitivity of these procedures to the certain properties of coatings imposes the main restriction to the accuracy of measurements. Therefore, the development and implementation of the approaches based on direct measurements of geometric parameters of the coating appears expedient. These methods often belong to the class of «destructive» and, in addition to measuring instruments, require the use of special equipment. To ensure the uniformity of measurements in the laboratory or technological control, these methods are isolated as a separate procedure (method) and must undergo metrological certification in accordance with GOST R 8.563–2009. We present implementation, metrological certification and practical application of the method for measuring thickness of coatings by crater-grinding method. The principles of technical implementation of test equipment, measurement procedure and calculation formulas are described. The results of evaluating the accuracy indicators of the proposed procedure by calculation and experimental methods are presented. In both cases, the relative error did not exceed 6%. The applicability of the developed technique is shown for a wide range of coating materials (from soft metals to superhard ceramics) of different thickness (with from units to hundreds of micrometers). Apart from the goals of process control and outgoing inspection, the method can be recommended as a reference measurement procedure for calibration of measures and adjusting samples for various types of thickness gauges.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

Endocarp Structural Components of Insect Resistance in Almond

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 526d-526
Author(s):  
M. Freeman ◽  
C. Walters ◽  
M.A. Thorpe ◽  
T. Gradziel
Keyword(s):  
Insect Resistance ◽  
Insect Pests ◽  
Stone Fruit ◽  
Structural Components ◽  
Insect Infestation ◽  
Insect Feeding ◽  
Kernel Development ◽  
X Ray ◽  
Seal Integrity ◽  
Structural Barrier

Almond, as with other stone fruit, possesses a highly lignified endocarp or shell. The dominant hard-shelled trait (D-) is positively associated with greater resistant to insect infestation than nuts expressing the paper-shelled (dd) trait. Hard-shelled genotypes have undesirable effects, including a lower kernel meat-to-nut crack-out ratio, greater kernel damage during mechanical shelling, and a reduction in plant energy available to kernel development. Histogenic analysis shows that the almond endocarp, unlike peach, has a tri-partite structure. Insect feeding studies have subsequently demonstrated that the inner endocarp layer, which is similar in both hard and paper-shelled types, is the most important structural barrier to insect infestation. Shell-seal integrity and X-ray studies have confirmed that discontinuities at the inner endocarp suture seal are the primary, though not the sole site of entry for insect pests. Paper-shelled almond selections with highly lignified and well-sealed inner endocarps show resistance levels comparable to hard shelled types but with crack-out ratios 30% to 40% higher. Pseudo-paper-shelled types have also been selected, in which a highly lignified outer endocarp is formed, but is retained by the fruit hull at dehiscence. An understanding of endocarp morphology and development is thus important in breeding for insect resistance as well as the commercial utilization of both kernel and hull.

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