Surface Layer Hardness of Austenitic Stainless Steel via Low Temperature Plasma Carburizing and/or Nitriding

2007 ◽  
Vol 561-565 ◽  
pp. 2477-2480 ◽  
Author(s):  
Masato Tsujikawa ◽  
S. Noguchi ◽  
N. Yamauchi ◽  
N. Ueda ◽  
T. Sone ◽  
...  
Keyword(s):  
Surface Layer ◽  
Nitrided Layer ◽  
Nitrogen Concentration ◽  
Austenitic Stainless Steels ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
X Ray Diffraction ◽  
Temperature Plasma ◽  
Carbon And Nitrogen ◽  
Plasma Carburizing

Surface layer hardness and concentration profiles of austenitic stainless steels after plasma carburizing and /or nitriding at 673 K were investigated. Carbon and nitrogen concentration were measured by glow discharge optical emission spectrometry (GDOES) and carbides or nitrides were detected by x-ray diffraction analysis (XRD) and TEM. The state of carbon at the treated surface was investigated by Raman spectroscopy. Separation of carburized layer and nitrided layer was observed in a simultaneous carburizing and nitriding plasma treatment.

scholarly journals High-efficiency method for recycling lithium from spent LiFePO4 cathode

2020 ◽  
Vol 9 (1) ◽  
pp. 1586-1593
Author(s):  
Tingting Yan ◽  
Shengwen Zhong ◽  
Miaomiao Zhou ◽  
Xiaoming Guo ◽  
Jingwei Hu ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
High Efficiency ◽  
Optical Emission ◽  
Extraction Process ◽  
Emission Spectrometry ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Moisture Analysis ◽  
Lifepo4 Cathode ◽  
Solid Liquid

Abstract The extraction of Li from the spent LiFePO4 cathode is enhanced by the selective removal using interactions between HCl and NaClO to dissolve the Li+ ion while Fe and P are retained in the structure. Several parameters, including the effects of dosage and drop acceleration of HCl and NaClO, reaction time, reaction temperature, and solid–liquid ratio on lithium leaching, were tested. The Total yields of lithium can achieve 97% after extraction process that lithium is extracted from the precipitated mother liquor, using an appropriate extraction agent that is a mixture of P507 and TBP and NF. The method also significantly reduced the use of acid and alkali, and the economic benefit of recycling is improved. Changes in composition, morphology, and structure of the material in the dissolution process are characterized by inductively coupled plasma optical emission spectrometry, scanning electron microscope, X-ray diffraction, particle size distribution instrument, and moisture analysis.

Investigation of Compound Layer Structures after Nitriding and Nitrocarburizing of Quenched and Tempered Steels

2021 ◽  
Vol 76 (3) ◽  
pp. 219-236
Author(s):  
M. Sommer ◽  
S. Hoja ◽  
M. Steinbacher ◽  
R. Fechte-Heinen
Keyword(s):  
Surface Layer ◽  
Phase Composition ◽  
Bulk Material ◽  
Fatigue Behavior ◽  
Nitrogen Concentration ◽  
Maximum Level ◽  
Compound Layer ◽  
X Ray Diffraction ◽  
Treatment Processes ◽  
Layer Structures

Abstract A compound layer is formed by ingress of nitrogen from an external nitrogen source into the surface layer and the formation of nitrides when the solubility of nitrogen in the bulk material is exceeded. In the surface layer, where the nitrogen concentration is at its maximum level, the nitrides form a closed layer. The compound layer continues to contain alloy nitrides which have formed from the carbides and other precipitates from the bulk material. The properties of the compound layer have a decisive influence on the wear and fatigue behavior of the loaded surfaces. The current investigations deal with the extensive characterization of compound layers that have been produced in heat treatment processes with the aim of producing stress-resistant nitriding layers. The commonly used nitriding and quench and temper (Q&T) steels 31CrMoV9 and 42CrMo4 served as examination material. The structure of the compound layers was varied within the nitriding trials regarding the phase composition, porosity and layer thicknesses. The phase composition of the compound layers was determined by special etching, scanning electron microscopy (SEM), X-ray diffraction and GDOES.

scholarly journals P2O5-Free Cerium Containing Glasses: Bioactivity and Cytocompatibility Evaluation

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3267
Author(s):  
Gigliola Lusvardi ◽  
Francesca Sgarbi Stabellini ◽  
Roberta Salvatori
Keyword(s):  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Doped Glasses ◽  
Plasma Mass Spectrometry ◽  
Sbf Solution ◽  
Xrd Techniques

(1) Background: valuation of the bioactivity and cytocompatibility of P2O5-free and CeO2 doped glasses. (2) Methods: all glasses are based on the Kokubo (K) composition and prepared by a melting method. Doped glassed, K1.2, K3.6 and K5.3 contain 1.2, 3.6, and 5.3 mol% of CeO2. Bioactivity and cytotoxicity tests were carried out in simulated body fluid (SBF) solution and murine osteocyte (MLO-Y4) cell lines, respectively. Leaching of ions concentration in SBF was determined by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). The surface of the glasses were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. (3) Results: P2O5-free cerium doped glasses are proactive according to European directives. Cerium increases durability and retards, but does not inhibit, (Ca10(PO4)6(OH)2, HA) formation at higher cerium amounts (K3.6 and K5.3); however, cell proliferation increases with the amount of cerium especially evident for K5.3. (4) Conclusions: These results enforce the use of P2O5-free cerium doped bioactive glasses as a new class of biomaterials.

scholarly journals Synthesis and characterization of Na-P1 (GIS) zeolite using a kaolinitic rock

2020 ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno ◽  
Alessandro Del Vecchio
Keyword(s):  
Inductively Coupled Plasma ◽  
Rietveld Method ◽  
Ambient Pressure ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Inductively Coupled

Abstract This work focuses on the hydrothermal synthesis of Na-P1 zeolite by using a kaolinite rock coming from Romana (Sassari, Italy). The kaolin is calcined at a temperature of 650 °C and then mixed with calculated quantities of NaOH. The synthesis runs are carried out at ambient pressure and at variable temperatures of 65 ° and 100 °C. For the first time compared to the past, the Na-P1 zeolite is synthesized without the use of additives and through a protocol that reduces both temperatures and synthesis times. The synthesis products are analysed by X-ray diffraction, high temperature X-ray diffraction, infrared spectroscopy, scanning electron microscopy and inductively coupled plasma optical emission spectrometry. The cell parameters are calculated using the Rietveld method. Density and specific surface area are also calculated. The absence of amorphous phases and impurities in synthetic powders is verified through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods.The results make the experimental protocol very promising for an industrial transfer.

scholarly journals Physicochemical Analysis of the Polydimethylsiloxane Interlayer Influence on a Hydroxyapatite Doped with Silver Coating

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
C. L. Popa ◽  
A. Groza ◽  
P. Chapon ◽  
C. S. Ciobanu ◽  
R. V. Ghita ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Composite Layer ◽  
Optical Emission ◽  
Physicochemical Analysis ◽  
Crystalline Form ◽  
Emission Spectrometry ◽  
Silver Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

We investigate by different complementary methods the processes occurring when a polydimethylsiloxane film is used as interlayer for a silver doped hydroxyapatite coating. The X-ray diffraction and Fourier Transform Infrared Spectroscopy measurements show that the hydroxyapatite doped with silver is in a crystalline form and someSiO44-ions formation takes place at the surface and in the bulk of the new hydroxyapatite doped with silver/polydimethylsiloxane composite layer. The possibility ofSiO44-ions incorporation in the structure of silver doped hydroxyapatite by the mechanism ofSiO44-/PO43-ions substitution is analysed. The new formed silver doped hydroxyapatite/polydimethylsiloxane composite layer is compact, homogeneous, with no cracks as it was shown by Scanning Electron Microscopy and Glow Discharge Optical Emission Spectrometry.

scholarly journals Effect of Proton Irradiation on the Defect Evolution of Zr/Nb Nanoscale Multilayers

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 535 ◽  
Author(s):  
Roman Laptev ◽  
Anton Lomygin ◽  
Dmitriy Krotkevich ◽  
Maxim Syrtanov ◽  
Egor Kashkarov ◽  
...  
Keyword(s):  
Proton Irradiation ◽  
Irradiation Time ◽  
Optical Emission ◽  
Positron Beam ◽  
Emission Spectrometry ◽  
Irradiation Effect ◽  
Self Healing ◽  
X Ray Diffraction ◽  
Distribution Study ◽  
Variable Energy

Nanoscale multilayer coatings (NMCs) with different crystal structures are considered as capable of self-healing after radiation damage due to the recombination of vacancies and interstitials. This work is focused on a defect distribution study of NMCs based on Zr/Nb layers (25/25 nm and 100/100 nm) after proton irradiation. Coatings with a total thickness of 1.05 ± 0.05 µm were irradiated by 900-keV protons using a pelletron-type electrostatic accelerator with an ion current of 2 µA for durations of 60 min to 120 min. The influence of the irradiation effect was studied by X-ray diffraction analysis (XRD), glow discharge optical emission spectrometry (GD–OES), and Doppler broadening spectroscopy using a variable energy positron beam. The results obtained by these methods are compatible and indicate that defect concentration of Zr/Nb NMCs remains unchanged or slightly decreases with increasing irradiation time.

Corrosion Behavior and Mechanism of Heat-Resistant Steel T91 in High-Temperature Carbon Dioxide Environment

2019 ◽  
Vol 944 ◽  
pp. 398-403
Author(s):  
Yong Gui ◽  
Zhi Yuan Liang ◽  
Miao Yu ◽  
Qin Xin Zhao
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Corrosion Behavior ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
X Ray Diffraction ◽  
Heat Resistant Steel ◽  
Scale Thickness ◽  
Corrosion Scale ◽  
Kinetics Of

Corrosion behavior of martensitic heat resisting steel T91 in high-temperature carbon dioxide environment at 500-700 °C was investigated. X-ray diffraction, scanning electron microscopy and glow-discharge optical emission spectrometry were employed to characterize the corrosion products. The results showed that the corrosion kinetics of T91 followed a parabolic law with experimental time. The oxide scale thickness of T91 followed an exponential growth law from 500 °C to 700 °C. Internal carburization was detected underneath the corrosion scale. What’s more, the carburization depth was larger than the corrosion scale. The variations of Cr and C elements distribution were discussed.

Sign in / Sign up

Export Citation Format

Share Document