Fabrication and Microstructure of Al-Based Hybrid Composite Reinforced by B4C and Ultra-Dispersed Tungsten

2011 ◽  
Vol 309-310 ◽  
pp. 249-254 ◽  
Author(s):  
Mikhail V. Gorshenkov ◽  
Sergey D. Kaloshkin ◽  
Victor V. Tcherdyntsev ◽  
Vladimir D. Danilov ◽  
Victor N. Gulbin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Thermal Expansion ◽  
Hybrid Composite ◽  
Hot Extrusion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antifriction Properties ◽  
Scanning Electron

Al-based hybrid composite reinforced by ultra-dispersed tungsten and B4C, was produced by mechanical alloying and hot extrusion. Structure of obtained composites was studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The compressive and tensile properties of these materials were investigated. Tribological tests showed high antifriction properties and wear resistance of composite containing B4C and tungsten. The dilatometric measurements showed that thermal expansion coefficient remains approximately constant up to 500 °C.

scholarly journals Microstructure and properties of boronizing layer of Fe-based powder metallurgy compacts prepared by boronizing and sintering simultaneously

2009 ◽  
Vol 41 (2) ◽  
pp. 199-207 ◽  
Author(s):  
X. Dong ◽  
J. Hu ◽  
Z. Huang ◽  
H. Wang ◽  
R. Gao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Wear Testing ◽  
Processing Temperature ◽  
X Ray Diffraction ◽  
Surface Microhardness ◽  
X Ray ◽  
Substrate Hardness ◽  
Scanning Electron

In this study, the boronized layers were formed on the surfaces of specimens with a composition of Fe-2 wt. % Cu-0.4 wt. % C by sintering and boronizing simultaneously, using a pack boronizing method. The processes were performed in the temperature range of 1050 - 1150 oC at a holding time of 4 hours in 97 % N2 and 3 % H2 atmosphere. Scanning electron microscopy examinations showed that the boronized layers formed on the surface of boronized and sintered specimens have a denticular morphology. The thicknesses of the boronized layers varied from 63 to 208 ?m depending on the processing temperature. The structures of the boronized layers were Fe2B and FeB confirmed by X-ray diffraction analysis. The microhardness values of boronized layers ranged from 1360 to 2066 HV0.3 much higher than that of substrate hardness which was about 186 HV0.3. Wear testing results showed that the wear resistance of the boronized and sintered specimens was significantly improved, resulting from increased surface microhardness.

Thermal Expansion of Cu-Ga-Sn Alloys

2014 ◽  
Vol 353 ◽  
pp. 137-142
Author(s):  
V.A. Bykov ◽  
T.V. Kulikova ◽  
K.Yu. Shunyaev ◽  
A.B. Shubin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Expansion ◽  
Temperature Dependence ◽  
Linear Thermal Expansion ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
Tin Alloys ◽  
X Ray ◽  
Scanning Electron

The thermal and microstructural properties of five copper-gallium-tin alloys (Cu-Ga-Sn) and two important intermetallic compounds Cu3Sn and CuGa2 have been investigated by dilatometry, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction. The temperature dependence of thermal expansion and coefficient of linear thermal expansion (CLTE) were obtained.

EFFECT OF Cr3C2 ADDITION ON THE MICROSTRUCTURE AND PROPERTIES OF LASER CLADDING NiCrBSi COATINGS

2019 ◽  
Vol 26 (06) ◽  
pp. 1850207 ◽  
Author(s):  
XUELONG PING ◽  
SHUTING SUN ◽  
FENG WANG ◽  
HANGUANG FU ◽  
JIAN LIN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Laser Cladding ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nicrbsi Coatings ◽  
Scanning Electron ◽  
Microhardness Tester

In this paper, the enhancement of NiCrBSi coatings by adding Cr3C2 were investigated. The NiCrBSi coatings with different additions of Cr3C2 were produced by laser cladding. The microstructure, hardness and wear resistance of the coatings were studied by optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness tester and M-200 wear tester. It is found that the main phases in the coatings are [Formula: see text]-Ni, Cr[Formula: see text]C6 and Cr7C3, and they also contain a small amount of CrB, Ni4B3 and Ni3Si2. Moreover, with the increase of Cr3C2 addition, the microhardness and wear resistance of coatings are obviously improved. When the addition of Cr3C2 is 20%, the wear resistance of the coating is the best, and the wear resistance of the coating increased by 191.2% than that of the Cr3C2-free coating. The wear resistance of coating decreases when the addition of Cr3C2 reaches 30%.

Microstructure and Wear Resistance of Laser Cladded Coatings on Copper Substrate

2011 ◽  
Vol 52-54 ◽  
pp. 1728-1731
Author(s):  
Wen Yan Wang ◽  
Gao Lu ◽  
Xiao Ming Dong ◽  
Jing Xu ◽  
Jing Pei Xie
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Laser Scanning ◽  
Copper Substrate ◽  
Resistance Testing ◽  
X Ray Diffraction ◽  
Pulsed Nd:Yag Laser ◽  
X Ray ◽  
Scanning Electron

In order to improve the wear resistance of continuous casting crystallizer, Co-based alloy coatings were prepared on copper substrate by a pulsed Nd:YAG laser. Scanning electron microscopy, X-ray diffraction, microhardness and wear resistance testing were employed to study the microstructure and properties of the cladding coatings. The results show that the friction coefficient and wear mass loss of the cladded coating with the volumn ratio of Stellite X-40：TiC：CaF2=60：10：30 are both the smallest; the average microhardness of the cladded coating is 496.2HV0.2 which is about five times higher than that of the substrate.

Thermal Cycling Degradation of YBa2Cu3O9−x Superconductors

1987 ◽  
Vol 99 ◽  
Author(s):  
Donald L. Kinser ◽  
Robert H. Magruder ◽  
Ronald A. Quarles ◽  
J. Dora Schaefer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Expansion ◽  
Thermal Cycling ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Anisotropy ◽  
Individual Grains ◽  
Scanning Electron

ABSTRACTThermal cycling for four cycles between 294 and 78°K has been observed to shift the superconducting transition temperature from 85 to 28°K. Samples cycled for 12 cycles between 373 and 78°K do not display superconductivity at temperatures down to 37°K. Guinier de Wolff X-ray diffraction observations of these samples reveal no crystallography changes during thermal cycling up to 12 cycles. Scanning electron microscopy studies of polished samples of the thermally cycled material revealed the presence of cracks in individual grains within each sample. The percentage of grains displaying cracks climbs rapidly with thermal cycling. We conclude that the loss of superconducting behavior is a consequence of removal of continuous paths but we are not, at this time, able to rationalize the shift of Tc with thermal cycling. We conclude that the thermal expansion anisotropy produces strains which lead to destructive fractures within the material.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

Structural Characterization of Gallbladder Stones Using Energy Dispersive X-ray Spectroscopy and X-ray Diffraction

2018 ◽  
Vol 21 (7) ◽  
pp. 495-500 ◽  
Author(s):  
Hassan A. Almarshad ◽  
Sayed M. Badawy ◽  
Abdalkarem F. Alsharari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Major Health Problem ◽  
X Ray ◽  
Gallbladder Stones ◽  
Pure Cholesterol ◽  
Scanning Electron

Aim and Objective: Formation of the gallbladder stones is a common disease and a major health problem. The present study aimed to identify the structures of the most common types of gallbladder stones using X-ray spectroscopic techniques, which provide information about the process of stone formation. Material and Method: Phase and elemental compositions of pure cholesterol and mixed gallstones removed from gallbladders of patients were studied using energy-dispersive X-ray spectroscopy combined with scanning electron microscopy analysis and X-ray diffraction. Results: The crystal structures of gallstones which coincide with standard patterns were confirmed by X-ray diffraction. Plate-like cholesterol crystals with laminar shaped and thin layered structures were clearly observed for gallstone of pure cholesterol by scanning electron microscopy; it also revealed different morphologies from mixed cholesterol stones. Elemental analysis of pure cholesterol and mixed gallstones using energy-dispersive X-ray spectroscopy confirmed the different formation processes of the different types of gallstones. Conclusion: The method of fast and reliable X-ray spectroscopic techniques has numerous advantages over the traditional chemical analysis and other analytical techniques. The results also revealed that the X-ray spectroscopy technique is a promising technique that can aid in understanding the pathogenesis of gallstone disease.

scholarly journals Analytical study of Buddha sculptures in Jingyin temple of Taiyuan, China

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaojian Bai ◽  
Chen Jia ◽  
Zhigen Chen ◽  
Yuxuan Gong ◽  
Huwei Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Analytical Study ◽  
Energy Dispersive Spectrometry ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Ancient China ◽  
X Ray ◽  
Unique Style ◽  
Scanning Electron

AbstractWith exquisite design and unique style, the painted sculptures of Tutang Buddha and two attendants Buddha in Jingyin Temple are precious cultural heritages of China. The sculpture of Tutang Buddha, which was carved from a mound and painted by ancient craftsmen, was rarely found in ancient China. However, due to natural and human factors, the sculptures were severely damaged. Obviously, they require urgent and appropriate protection and restoration. In this study, samples taken from the sculptures were analysed through multiple analytical techniques, including scanning electron microscopy with energy dispersive spectrometry (SEM–EDS), Raman spectroscopy, X-ray diffraction (XRD), optical microscopy (OM) and granulometry. The analysis results enable us to infer the techniques used by the craftsmen in making the sculptures and provide a reliable evidence for the conservation and future protection of these and similar sculptures.

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