Characterization of Laser Cladding WC-Ti Composite Coatings

2008 ◽  
Vol 368-372 ◽  
pp. 1316-1318 ◽  
Author(s):  
Jian Bin Zhang ◽  
Ding Fan ◽  
Min Zheng ◽  
Yao Ning Sun ◽  
Yu Feng Zheng
Keyword(s):  
Laser Cladding ◽  
Continuous Wave ◽  
Composite Coatings ◽  
Commercial Purity ◽  
X Ray ◽  
Commercial Purity Titanium ◽  
Clad Layer ◽  
Scanning Electron ◽  
Mechanism Of The Reaction

The applications of titanium and titanium alloys under severe wear conditions are highly restricted due to their low hardness and poor tribological properties. To improve the hardness and wear resistance, laser cladding of commercial purity titanium was carried out with a 5 kW continuous wave CO2 laser. WC powders and Ti powders were mixed for cladding in different proportions. The phases of clad layer were characterized by scanning electron microscopy, X-ray diffractometer and energydispersive X-ray spectroscopy. The mechanism of the reaction between melted WC and Ti is discussed.

Effect of Powder Size and Volume Fraction of WC on the Microstructure of Laser Cladding WC-NiCrBSi Composite Coatings

2011 ◽  
Vol 121-126 ◽  
pp. 105-109
Author(s):  
Y.Y. Wang ◽  
Y.F. Gong ◽  
T.F. Sun ◽  
P.F. Ni ◽  
Z. Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Laser Cladding ◽  
Laser Power ◽  
Volume Fraction ◽  
Composite Coatings ◽  
Nonuniform Distribution ◽  
Powder Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

WC-NiCrBSi composite coatings on 0.45 % carbon steel were fabricated by laser cladding. The volume fraction (33, 43 and 60 vol. %) of WC particles with the powder size of 2 μm, 5 μm and 50 μm were added respectively into NiCrBSi powders to deposit composite coatings. The microstructure of the powders and the coatings were examined by scanning electron microscope (SEM) and X-ray diffraction (XRD). Results show that the compactness and uniformity of the coatings are good when WC particles size was 2 μm and 5 μm. However nonuniform distribution and deposit of WC particles on the bottom of the coating will occur when the powder size of WC particles was 50 μm and the volume fraction of WC was 33 %. When the volume of WC addition was higher than 60 %, the volume fraction of the retained WC particles in the coatings is obviously decreased. The dissolving and decomposing of WC increase with decreasing the powder size and increasing the volume of WC addition and the laser power.

scholarly journals EFFECT OF TiO2 NANOPARTICLES ON THE MECHANICAL AND ANTICORROSIVE PROPERTIES OF Zn-Ni COMPOSITE COATINGS

2019 ◽  
Vol 25 (2) ◽  
pp. 107
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Okba Belahssen
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Film Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Mild Steel Substrate

<p class="AMSmaintext1"><span lang="EN-GB">In this paper, we are interested in the study of electrochemical, morphological and structural characteristics of the properties of the deposits of Zn-Ni-TiO<sub>2</sub> obtained by electrodeposition on the mild steel substrate in a bath of sulfate. The principal aim is to improve the coatings with better properties, by incorporation of titanium oxide, which is a hard compound, chemically stable and irreducible. The characterization of the coatings was carried out by scanning electron microscopy (SEM) and by X-ray diffraction. The morphology of the film surface varies with the concentration of oxide titanium and it was found higher values of microhardness. Electrochemical characterization of the composites had been carried out through potentiodynamic polarization. The results showed that better corrosion resistance with the incorporation of oxide titanium.</span></p>

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.

scholarly journals Characterization of a Mahamayuri Vidyarajni Sutra excavated in Lu’an, China

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Liu Liu ◽  
Decai Gong ◽  
Zhengquan Yao ◽  
Liangjie Xu ◽  
Zhanyun Zhu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tang Dynasty ◽  
Optical Microscope ◽  
Lead White ◽  
Scientific Methods ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Scanning Electron

Abstract Historically, sutras played an important role in spreading Buddhist faith and doctrine, and today these remain important records of Buddhist thought and culture. A Mahamayuri Vidyarajni Sutra with polychrome paintings was found inside the cavity on top of the Nanmen Buddhist pagoda, built in the early Tang dynasty (618–627 CE) and located in Anhui Province, China. Textile was found on the preface which is strongly degraded and fragile. Unfortunately, the whole sutra is under severe degradation and is incomplete. Technical analysis based on scientific methods will benefits the conservation of the sutra. Optical microscopy (OM), micro-Raman spectroscopy combined with optical microscope (Raman), scanning electron microscopy in combination with energy dispersive X-ray analysis (SEM–EDS) and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize the pigment and gilded material, as well as the paper fiber and textile. Pigments such as cinnabar, minium, paratacamite, azurite, lead white were found. Gilded material was identified as gold. A five-heddle warp satin, made of silk, was found as the textile on the preface of the sutra. The sutra’s preface and inner pages were made of paper comprised of bamboo and bark. As a magnificent yet recondite treasure of Buddhism, the sutra was analyzed for a better understanding of the material. A conservation project of the sutra will be scheduled accordingly.

Preliminary Preparation and Characterization Studies of Cellulose from Merbau (Intsia bijuga)

2012 ◽  
Vol 620 ◽  
pp. 314-319
Author(s):  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
Saadah Abdul Rahman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Alkaline Treatment ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Preliminary Preparation ◽  
Characterization Studies ◽  
Scanning Electron

Hardwood is wood from angiosperm trees. The characteristic of hardwood include flowers, endosperm within seeds and the production of fruits that contain the seeds. This paper aims to discuss the preparation and characterization of cellulose obtained from hardwood. The hardwood Merbau (Intsia bijuga) was chosen as raw material in this study. Alkaline treatment and delignification methods were used for the preparation of cellulose. Acid hydrolysis was employed to produce cellulose nanocrystal (CNC). The treated and untreated samples were characterized using x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The final product, from both trated and untreated samples were then compared.

Preparation of Carbon Nanofibers from Polyacrylonitrile Nanofibers by Electrospinning

2011 ◽  
Vol 415-417 ◽  
pp. 642-647
Author(s):  
En Zhong Li ◽  
Da Xiang Yang ◽  
Wei Ling Guo ◽  
Hai Dou Wang ◽  
Bin Shi Xu
Keyword(s):  
Electron Microscope ◽  
Carbon Nanofibers ◽  
Photoelectron Spectroscopy ◽  
Solution Concentration ◽  
Dimethyl Formamide ◽  
Ultrafine Fibers ◽  
X Ray ◽  
Scanning Electron ◽  
Pan Fibers

Ultrafine fibers were electrospun from polyacrylonitrile (PAN)/N,N-dimethyl formamide (DMF) solution as a precursor of carbon nanofibers. The effects of solution concentration, applied voltage and flow rate on preparation and morphologies of electrospun PAN fibers were investigated. Morphologies of the green fibers, stabilized fibers and carbonized fibers were compared by scanning electron microscope (SEM). The diameter of PAN nanofibers is about 450nm and the distribution of diameter is well-proportioned. Characterization of the elements changes of fibers were performed by X-ray photoelectron spectroscopy (XPS).

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

Characterization of Al65.0Cu32.9Co2.1 Alloy Containing Nanofibres

2012 ◽  
Vol 186 ◽  
pp. 212-215
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Grzegorz Dercz ◽  
Wojciech Gurdziel
Keyword(s):  
Electron Microscopy ◽  
Average Diameter ◽  
Chemical Compositions ◽  
X Ray ◽  
Transmission Electron ◽  
Orthogonal Set ◽  
T Phase ◽  
Terminal Area ◽  
Scanning Electron

Microstructure of terminal area of Al65Cu32.9Co2.1ingots (numbers indicate at.%), obtained via directional solidification was studied. Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray powder diffraction were applied. Point microanalysis by Scanning Electron Microscope was used for examination of chemical compositions of alloy phases. It was found that tetragonal θ phase of Al2Cu stoichiometric formula was the dominate phase (matrix). Additionally the alloy contained orthogonal set of nanofibres of Al7Cu2Co T phase with the average diameter of 50-500 nm and oval areas of hexagonal Al3(Cu,Co)2H-phase, surrounded by monoclinic AlCu η1phase rim. Inside some areas of H-phase cores of decagonal quasicrystalline D phase were observed.

Characterization of hydrofluoric acid treated Y–Ba–Cu–O oxides

1989 ◽  
Vol 4 (6) ◽  
pp. 1320-1325 ◽  
Author(s):  
Q. X. Jia ◽  
W. A. Anderson
Keyword(s):  
Hydrofluoric Acid ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Surface Passivation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zero Resistance ◽  
Reaction With Water ◽  
Scanning Electron

Effects of hydrofluoric acid (HF) treatment on the properties of Y–Ba–Cu–O oxides were investigated. No obvious etching of bulk Y–Ba–Cu–O and no degradation of zero resistance temperature were observed even though the oxides were placed into 49% HF solution for up to 20 h. Surface passivation of Y–Ba–Cu–O due to HF immersion was verified by subsequent immersion of Y–Ba–Cu–O in water. A thin layer of amorphous fluoride formed on the surface of the Y–Ba–Cu–O during HF treatment, which limited further reaction between Y–Ba–Cu–O and HF, and later reaction with water. Thin film Y–Ba–Cu–O was passivated by HF vapors and showed no degradation in Tc-zero after 30 min immersion in water. The properties of the surface layer of Y–Ba–Cu–O oxide after HF treatment are reported from Auger electron spectroscopy, x-ray diffraction, and scanning electron microscopy studies.

Sign in / Sign up

Export Citation Format

Share Document