scholarly journals Cathodic Cage Plasma Nitriding: An Innovative Technique

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
R. R. M. de Sousa ◽  
F. O. de Araújo ◽  
J. A. P. da Costa ◽  
A. de S. Brandim ◽  
R. A. de Brito ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Edge Effect ◽  
Plasma Nitriding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microhardness Test ◽  
Ionic Nitriding ◽  
Aisi 316 ◽  
A New Technique ◽  
Cylindrical Samples

Cylindrical samples of AISI 1020, AISI 316, and AISI 420 steels, with different heights, were simultaneously treated by a new technique of ionic nitriding, entitled cathodic cage plasma nitriding (CCPN), in order to evaluate the efficiency of this technique to produce nitrided layers with better properties compared with those obtained using conventional ionic nitriding technique. This method is able to eliminate the edge effect in the samples, promoting a better uniformity of temperature, and consequently, a smaller variation of the thickness/height relation can be obtained. The compound layers were characterized by X-ray diffraction, optical microscopy, and microhardness test profile. The results were compared with the properties of samples obtained with the conventional nitriding, for the three steel types. It was verified that samples treated by CCPN process presented, at the same temperature, a better uniformity in the thickness and absence of the edge effect.

scholarly journals Characterization of the expanded austenite developed on AISI 316 LM steel by plasma nitriding

2017 ◽  
Vol 53 (1) ◽  
pp. 47-52 ◽  
Author(s):  
M. Keddam ◽  
T. Thiriet ◽  
G. Marcos ◽  
T. Czerwiec
Keyword(s):  
Optical Emission Spectroscopy ◽  
Plasma Nitriding ◽  
Optical Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compressive Stresses ◽  
Expanded Austenite ◽  
Aisi 316 ◽  
Kinetics Of

AISI 316 LM samples were plasma nitrided at a temperature of 380?C for different times between 0.5 and 8 h in a 85%N2- 15%H2 gas mixture. Different experimental techniques such as: optical microscopy (OM), X- ray diffraction (XRD ) and glow discharge optical emission spectroscopy (GDOES) were used to characterize the expanded austenite layer formed at the surface of AISI 316 LM stainless steel. The microscopical observations revealed the presence of the expanded austenite with a mean layer thickness between 1.90 and 4.31 ?m. The growth kinetics of expanded austenite was also investigated. In addition, both the compressive stresses in the expanded austenite layer and the compositional strains were estimated by means of a simple mechanical model based on the XRD results.

Synthesis and Properties of Thermotropic Liquid Crystalline Polyesters with Flexible Polymethylene Spacer

2010 ◽  
Vol 428-429 ◽  
pp. 126-131
Author(s):  
Wei Zhong Lu ◽  
Chun Wei ◽  
Qui Shan Gao
Keyword(s):  
Optical Microscopy ◽  
Liquid Crystalline ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Morphology ◽  
Temperature Ranges ◽  
Ft Ir ◽  
Diffraction Peaks ◽  
Ubbelohde Viscometer

Polymethylene bis(p-hydroxybenzoates) were prepared from methyl p-hydroxybenzoate and different diols by melted transesterification reaction. Three liquid crystalline polyesters were synthesized from terephthaloyl dichloride and polymethylene bis(p-hydroxybenzoates). Its structure, morphology and properties were characterized by Ubbelohde viscometer, Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), polarized optical microscopy (POM) with a hot stage, and wide-angle X-ray diffraction (WAXD). Results indicated that the intrinsic viscosities were between 0.088 and 0.210 dL/g. Optical microscopy showed that the TLCP has a highly threaded liquid crystalline texture and a high birefringent schlieren texture character of nematic phase and has wider mesophase temperature ranges for all polyesters. DSC analysis were found that the melting point (Tm), isotropic temperature (Ti) of TLCPs decreased and the temperature range of the liquid crystalline phase became wider with increased number of methylene spacers in the polyester. The WAXD results showed that TLCPs owned two strong diffraction peaks at 2θ near 19° and 23°.

scholarly journals Mössbauer study of Fe phases in terrestrial olivine basalts from southern Egypt

Mineralogia ◽  
2013 ◽  
Vol 44 (1-2) ◽  
pp. 3-12 ◽  
Author(s):  
Kamaleldin M. Hassan ◽  
Julius Dekan
Keyword(s):  
Optical Microscopy ◽  
Crystal Chemistry ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Mössbauer Study ◽  
Hyperfine Parameters ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Oxidized Iron

AbstractOlivine basalts from southern Egypt were studied by 57Fe Mössbauer spectroscopy at 297 and 77 K, and by optical microscopy and X-ray diffraction. The 57Fe Mössbauer spectra show three-magnetic sextets, three doublets of ferrous (Fe2+), and a weak ferric (Fe3+) doublet that is attributable to a nanophase oxide (npOx). The magnetic sextets relate to titanomagnetite and the Fe2+ doublets to olivine, pyroxene, and ulvöspinel. Variations in the hyperfine parameters of the various Fe components are attributed to changes in the local crystal chemistry. The intensity of oxidation (Fe3+/ΣFe) in the rocks varies from 20-27% with the oxidized iron largely residing in the titanomagnetite.

scholarly journals Titania powder activation and rutile ceramics structure formation

2009 ◽  
Vol 41 (1) ◽  
pp. 27-33 ◽  
Author(s):  
I.R. Ziganshin ◽  
S.E. Porozova ◽  
A.E. Stolina ◽  
M.F. Torsunov
Keyword(s):  
Raman Spectroscopy ◽  
Porous Materials ◽  
Optical Microscopy ◽  
Aqueous Medium ◽  
Structure Formation ◽  
Mechanochemical Activation ◽  
Organic Additives ◽  
X Ray Diffraction ◽  
X Ray ◽  
Titania Powder

Impact of mechanochemical activation (MCA) in aqueous medium with various organic additives on commercial titania powder and products made of it has been investigated by X-ray diffraction, optical microscopy and Raman spectroscopy. Agar-agar additive has been shown to offer promise for activation of titania powders used in obtaining both dense and porous materials.

EFFECT OF NITROGEN AMOUNT ON TRIBOLOGICAL BEHAVIOR OF PLASMA NITRIDED 31CrMoV9 STEEL

2019 ◽  
Vol 26 (07) ◽  
pp. 1850217 ◽  
Author(s):  
O. ÇOMAKLI ◽  
A. F. YETIM ◽  
B. KARACA ◽  
A. ÇELIK
Keyword(s):  
Wear Resistance ◽  
Tribological Behavior ◽  
Wear Behavior ◽  
Plasma Nitriding ◽  
Surface Hardness ◽  
Compound Layer ◽  
Gas Mixture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pin On Disk

The 31CrMoV9 steels were plasma nitrided under different gas mixture ratios to investigate an influence of nitrogen amount on wear behavior. The structure, mechanical and tribological behavior of untreated and nitrided 31CrMoV9 steels were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), microhardness device, 3D profilometer and pin-on-disk wear tester. The analysis outcomes displayed that the compound layer consists of nitride phases (Fe2N, Fe3N, Fe4N and CrN). Additionally, the thickness of the compound layers, surface hardness and roughness increased with increasing nitrogen amount in the gas mixture. The highest friction coefficient value was obtained at nitrogen amount of 50%, but the lowest value was seen at nitrogen amount of 6%. It was observed that wear resistance of 31CrMoV9 steel improved after plasma nitriding, and the best wear resistance was also obtained from plasma nitrided sample at the gas mixture of 94% H[Formula: see text]% N2.

Structural study of cokes using optical microscopy and X-ray diffraction

Fuel ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Asao Ōya ◽  
Zhanfen Qian ◽  
Harry Marsh
Keyword(s):  
Optical Microscopy ◽  
Structural Study ◽  
X Ray Diffraction ◽  
X Ray

A Novel Technique of Flyash Utilization: Preparation of Silica from Flyash by Alkali Leaching

2010 ◽  
Vol 434-435 ◽  
pp. 814-815
Author(s):  
An Ran Guo ◽  
Jia Chen Liu ◽  
Yi Bing Sun ◽  
Wen Jun Lian ◽  
Lu Yang
Keyword(s):  
High Purity ◽  
Sodium Hydroxide Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Novel Technique ◽  
Reinforcing Agent ◽  
Alkali Leaching ◽  
A New Technique ◽  
Fluorescence Spectrometer ◽  
Scanning Electron

A new technique of flyash utilization was presented and high-purity silica was prepared by alkali leaching. The flyash was added into sodium hydroxide solution, and then the suspension was heated to 115 °C for 30 min. After filtrated, the filtrate was collected and carbon dioxide was imported into the solution. Finally, the silica would precipitate from the solution. The silica was characterized by scanning electron microscopy, X-ray diffraction and X-ray fluorescence spectrometer. The high-purity silica prepared from flyash was qualified for the rubber reinforcing agent used in shoemaking.

Microstructural Evaluation of Clayey Ceramic Incorporated with Sludge from Paper Manufacturing

2016 ◽  
Vol 881 ◽  
pp. 422-426
Author(s):  
Carlos Maurício Fontes Vieira ◽  
Regina Maria Pinheiro ◽  
Sergio Neves Monteiro
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Paper Making ◽  
Paper Manufacturing ◽  
Microstructural Evaluation ◽  
Calcium Compounds ◽  
Scanning Electron

This work has for objective to evaluate the microstructure of clayey ceramic incorporated with a waste in the form of sludge generated during treatment of effluent of a paper making industry. The microstructure of ceramics incorporated with 0 and 10 wt.% of waste, and then fired at 600°C, was evaluated by optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the waste changes the microstructure of the clayey ceramic increasing the porosity, as well as forming new crystalline phases, mainly with calcium compounds.

Microstructure and Compound Developed from the Ce-As-Fe at 1173K

2014 ◽  
Vol 887-888 ◽  
pp. 467-470
Author(s):  
Si Si Zhu ◽  
Jin Zhu Zhang ◽  
Wei Yu Yang
Keyword(s):  
Optical Microscopy ◽  
Ternary Compound ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
Gray Phase ◽  
Interaction Product ◽  
X Ray ◽  
Probe Microscopy ◽  
Electronic Probe ◽  
Microscopy Analysis

In this study, a certain amount of Cerium and Arsenic were closed in the barrel-shaped cylinder machined by H08 steel, heated to 1173 K for 50 h, and the interaction among the cerium, arsenic and iron in the barrel-shaped cylinder was studied by X-ray diffraction, optical microscopy and electronic probe microscopy analysis. The result shows that the gray phase is the ternary compound Ce12Fe57.5As41, and the ternary compound Ce12Fe57.5As41 is the main interaction product when the atomic ratio of Ce to As is 1:3. The eutectic compound Fe2As can be precipitated from ferrite with the temperature decreasing.

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