Microstructure and Growth Mechanism of Glucose-Carburized Nickel Substrates

2013 ◽  
Vol 716 ◽  
pp. 153-158
Author(s):  
E.M. Pechlivani ◽  
G. Stergioudis ◽  
E. Pavlidou ◽  
S. Skolianos ◽  
D. Tsipas
Keyword(s):  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Temperature Treatment ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Nickel Substrates ◽  
Current Densities

In this research, efforts were made to study the modification of microstructure of pure Ni matrices. Modification was attempted using glucose as carburizing medium under a control of heat treatment conditions. Nickel plates were carburized under vacuum conditions at 380°C and 650°C for 3 hours. In order to determine the parameters of the carburizing, thermal properties of glucose along with the thermochemical behavior were examined by Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). The characterization of the microstructure of the carburized specimens was investigated by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). For analyzing the effect of temperature treatment on corrosion resistance, electrochemical corrosion tests were conducted. It was observed that the polarization curves for carburized samples at 380°C were shifted to lower corrosion current densities. Consequently, lower corrosion rates were achieved for these samples preventing the formation of extensive corrosion over their surfaces comparing with carburized Nickel substrates at 650°C.

scholarly journals A microstructural and corrosion resistance study of (Zr, Si, Ti)N-Ni coatings produced through co-sputtering

DYNA ◽  
2018 ◽  
Vol 85 (207) ◽  
pp. 192-197 ◽  
Author(s):  
Estrella Natali Borja-Goyeneche ◽  
Jhon Jairo Olaya-Florez
Keyword(s):  
Corrosion Resistance ◽  
Nickel Content ◽  
Corrosion Current ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Current Densities ◽  
Fcc Phase

This work researches the influence of the nickel content on the structural and anticorrosive properties of ZrSiTiN films deposited by means of reactive co-sputtering on alloys of Ti6Al4V. The morphology and structure were analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the chemical composition was identified via X-ray scattering spectroscopy (EDS). The corrosion resistance was studied using potentiodynamic polarization (PP) tests employing a 3.5% by weight NaCl solution. In the films, an increase of Ni up to 6.97 at% was observed, while in XRD the FCC phase of (Zr, Ti) N was identified, with a mixed orientation in planes (111) and (200), which tended to diminish with the increase of Ni. Finally, with the addition of Ni, the corrosion current densities were reduced from 5.56 𝑥 10−8 to 2.64 𝑥 10−9 𝐴/𝑐m2. The improvement in the corrosion resistance is due to the effect of the Ni on the microstructure of the system (Zr, Ti) N, which can improve the quality of the passive film and prevent crystalline defects and corrosion zones.

Novel Synthesis and Characterization of Titanium Carbide Coatings on Graphite Flakes

2013 ◽  
Vol 634-638 ◽  
pp. 3052-3055 ◽  
Author(s):  
Jun Ding ◽  
Wen Jie Yuan ◽  
Cheng Ji Deng ◽  
Hong Xi Zhu
Keyword(s):  
Titanium Carbide ◽  
Dominant Role ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Novel Synthesis ◽  
Carbide Coatings ◽  
Coating Formation ◽  
Titanium Powders

Titanium carbide coatings were synthesized by reacting with titanium powders in NaF-NaCl based salt on surface of graphite at 1100-1400 °C in argon (Ar). The effect of temperature of heat treatment on TiC coatings properties was studied. Phase composition and microstructure of the TiC coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray spectroscopy (EDS). The “template-growth” mechanism plays a dominant role in the coating formation process.

Nucleation, Crystallization and Characterization of Mica-Based Glass-Ceramics with Fluorapatite

2014 ◽  
Vol 936 ◽  
pp. 164-169 ◽  
Author(s):  
Jia Bai ◽  
Duangrudee Chaysuwan
Keyword(s):  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Soaking Time ◽  
X Ray ◽  
Optimal Heat Treatment ◽  
Treatment Conditions ◽  
Quenched Glass ◽  
Dental Applications ◽  
Soaking Temperature

The glass system of SiO2-Al2O3-MgO-MgF2-SrCO3-CaCO3-CaF2-P2O5 was used to prepare machinable glass-ceramics for restorative dental applications. The aim of this study was to apply various heat treatments to produce mica-based glass-ceramics. Differential Thermal Analysis (DTA) was used to determine the optimal heat treatment conditions for nucleation and growth of the crystalline phases in the quenched glass. It was found that the optimum nucleation temperatures for the first and the second crystallization temperatures (Tp1 and Tp2) were 642°C and 635°C, respectively, and the optimum nucleation times were between 2 and 4 hours. X-Ray Diffraction (XRD) showed the phases developed were anorthite, calcium-mica, fluorapatite, strontium apatite, forsterite, fluorite and stishovite phases. The microstructures of glass-ceramics were observed by Scanning electron microscope (SEM), found to exhibit plate-like mica crystals with high interlocking and randomly oriented with a higher soaking temperature and prolongation of the soaking time for crystallization.

scholarly journals Effect of Current Density on the Performance of Ni–P–ZrO2–CeO2 Composite Coatings Prepared by Jet-Electrodeposition

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 616
Author(s):  
Zhaoyang Song ◽  
Hongwen Zhang ◽  
Xiuqing Fu ◽  
Jinran Lin ◽  
Moqi Shen ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Current Density ◽  
Composite Coatings ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
X Ray Diffraction ◽  
X Ray ◽  
Jet Electrodeposition ◽  
Electrochemical Corrosion Resistance

The objective of this study was to improve the surface properties, hardness, wear resistance and electrochemical corrosion resistance of #45 steel. To this end, Ni–P–ZrO2–CeO2 composite coatings were prepared on the surface of #45 steel using the jet-electrodeposition technique by varying the current density from 20 to 60 A/dm2. The effect of current density on the performance of the composite coatings was evaluated. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were applied to explore the surface topography, elemental composition, hardness and electrochemical corrosion resistance of the composite coatings. The results showed that with the increase in the current density, the hardness, wear resistance, and electrochemical corrosion resistance tends to increase first and then decrease. At a current density of 40 A/dm2, the hardness reached a maximum of 688.9 HV0.1, the corrosion current reached a minimum of 8.2501 × 10−5 A·cm−2, and the corrosion potential reached a maximum of −0.45957 V. At these values, the performance of the composite coatings was optimal.

Thermal Characterization of Neodymium-Barium-Copper Ceramic (NBCo Ceramic) Synthesized from Barium Carbonate

2016 ◽  
Vol 869 ◽  
pp. 74-78
Author(s):  
José Passos Fernandes ◽  
A. Tibola ◽  
M. Lorensetti ◽  
G.W. Duarte ◽  
M.R. Rocha ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Barium Carbonate ◽  
Thermal Characterization ◽  
Neodymium Oxide ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Barium Copper

This work presents a study about thermal properties of a ceramic material based on NdBaCu system sintered with barium carbonate. These specialized ceramics are manufactured under special conditions and due to its unique electrical and thermal properties are frequently used by the electronic industry. Ceramics containing neodymium-barium-copper (NdBaCu) exhibit high conductivity at low temperatures. In this work, the ceramic samples were sintered with different percentage of barium carbonate, cupric and neodymium oxide and were characterized with Termogravimetric Analysis (TGA), Differential Scanning Calorimetric (DSC), Thermal Dilatometric Analysis (TDA) and X-Ray Diffraction Analysis (DRX). The results showed that the electrical conductivity of NdBaCu system is dependent on the calcination temperature. In turn, the complete calcination is dependent on the barium percentage and the thermal treatment conditions.

Influence of Homogenization Treatment on Electrochemical Behavior of the Mg-0.8wt%Ga-0.8wt%In Anode Materials

2014 ◽  
Vol 788 ◽  
pp. 1-6
Author(s):  
Feng Yan ◽  
Ri Chu Wang ◽  
Chao Qun Peng
Keyword(s):  
Corrosion Product ◽  
Anode Materials ◽  
Electrochemical Corrosion ◽  
Secondary Phase ◽  
Corrosion Current ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Homogenization Treatment ◽  
X Ray ◽  
Electrochemical Corrosion Behavior

The effects of homogenization treatment on the electrochemical corrosion behavior of Mg-0.8wt%Ga-0.8wt%In anode materials were investigated by the polarization and galvanostatic curves tests. The scanning electron micrographs of the secondary phase after heat treatment and the corroded surface of the specimens were observed. The corrosion product of the Mg-0.8wt%Ga-0.8wt%In alloy was determined by X-ray diffraction. The results show that the intergranular compound dissolved in the Mg matrix in the Mg-0.8wt%Ga-0.8wt%In after homogenizing at 673K for 24h. The least corrosion current density, 0.029mA/cm2, appeared in this specimen due to the least corrosion driving force. The corrosion of the Mg-0.8wt%Ga-0.8wt%In alloy in a 3.5% NaCl solution was generous corrosion and pitting attack. The corrosion product has been found to be mainly Mg (OH)2.

scholarly journals Processing and characterization of CaTiO3 perovskite ceramics

2014 ◽  
Vol 8 (2) ◽  
pp. 53-57 ◽  
Author(s):  
Guilherme Gralik ◽  
Alessandra Thomsen ◽  
Cristian Moraes ◽  
Fabiano Raupp-Pereira ◽  
Dachamir Hotza
Keyword(s):  
Calcium Titanate ◽  
Thermal Shrinkage ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Insulating Materials ◽  
X Ray ◽  
Molar Ratios ◽  
Treatment Conditions ◽  
Semiconducting Ceramics

Calcium titanate (CaTiO3) ceramics with perovskite structure were produced by solid state reaction. Calcium carbonate (CaCO3) and titanium dioxide (TiO2) were mixed (in molar ratios 1/1 and 3/2), and the obtained mixtures were calcined at 1150 ?C in successive thermal cycles. The obtained samples were characterized by differential thermal analysis, thermogravimetry, X-ray diffraction, measurement of particle size distribution and linear thermal shrinkage. XRD results indicated that the samples have perovskite CaTiO3 structure with small amount of secondary CaO and TiO2 phases, and their phase composition depends on the heat treatment conditions. The measured values of electrical resistivity were within the characteristic range of insulating materials and approach values corresponding to semiconducting ceramics.

SYNTHESIS AND CHARACTERIZATION OF α-Fe2O3@ATO NANOCOMPOSITE PARTICLES

2008 ◽  
Vol 15 (05) ◽  
pp. 545-550 ◽  
Author(s):  
YIN-CUN ZHU ◽  
JI-SEN JIANG
Keyword(s):  
Weight Ratio ◽  
Precipitation Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Nanocomposite Particles ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Treatment Conditions ◽  
Transmission Electron

α- Fe 2 O 3@ATO (antimony doped tin oxide) nanocomposite particles with core–shell structure were prepared by homogeneous precipitation method using monodispersed α- Fe 2 O 3 (hematite) nanoparticles as cores, SnCl 4 · 5 H 2 O and SbCl 3 as the precursor of the shell. The morphology and structure of the nanocomposite particles were studied with transmission electron microscopy and X-ray diffraction, respectively. The electricity properties of the nanocomposite were also investigated in terms of coating amount, molar ratio of element Sb to Sn , and heat treatment conditions. The results showed that the conditions of ATO/α- Fe 2 O 3 (weight ratio) = 70%, n( Sb )/n( Sn ) = 10%, calcined at 700°C for 1 h were optimal for the conductivity of the nanocomposite.

Characterization of Ti Alloys Bombarded by keV Deuterium Ions

1992 ◽  
Vol 268 ◽  
Author(s):  
G.P. Chambers ◽  
G. K. Hubler ◽  
J.A. Sprague ◽  
K.S. Grabowski
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ti Alloys ◽  
Transmission Electron ◽  
Before And After ◽  
Current Densities ◽  
Deuterium Gas ◽  
Secondary Ion

ABSTRACTThin Ti films have been bombarded at room temperature with 350–500 eV deuterium ions at current densities up to 0.5 mA/cm2. Analysis using scanning electron microscopy, x-ray diffraction, transmission electron microscopy, and secondary ion mass spectroscopy were carried out before and after bombardment. It was determined that deuterium diffuses rapidly throughout the Ti film, that the films were in a state of high compressive stress, and that the TiD2 phase was formed. No evidence of deuterium gas bubbles was found.

scholarly journals Electrochemical corrosion of Al-Pd alloys in HCl and NaOH solutions

2017 ◽  
Vol 53 (3) ◽  
pp. 333-340 ◽  
Author(s):  
M. Palcut ◽  
L. Ďuriska ◽  
M. Spoták ◽  
M. Vrbovský ◽  
Z. Gerhátová ◽  
...  
Keyword(s):  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Chemical Compositions ◽  
Corrosion Performance ◽  
X Ray Diffraction ◽  
Arc Melting ◽  
Electrode Cell ◽  
Current Densities ◽  
Basic Solutions ◽  
Alloy Microstructure

The corrosion performance of as-solidified Al-Pd alloys in HCl and NaOH aqueous solutions is investigated in this work. Four different alloys (Al88Pd12, Al77Pd23, Al72Pd28 and Al67Pd33, element concentrations are given in at.%) were prepared from high purity Al and Pd lumps by arc-melting in Ar. Subsequently, the alloy microstructure and phase occurrence were investigated by a combination of scanning electron microscopy and room-temperature powder X-ray diffraction. The assolidified Al-Pd alloys were found to consist of several single-phase microstructure constituents with various structures and chemical compositions, including structurally complex intermetallic phases. The polished surfaces of the Al-Pd alloys were subjected to electrochemical polarization in aqueous HCl and NaOH solutions (0.01 mol.dm-3) at 21?2?C. The corrosion experiments were conducted in a standard 3-electrode cell controlled by potentiostat. The corrosion potentials and corrosion current densities were determined by Tafel extrapolation of the experimental polarization curves. Phase dissolution has been observed on the alloy surfaces and some of the phases were preferentially corroded. The effects of the alloy microstructure and the phase occurrence are evaluated. The local nobility of individual intermetallic compounds is discussed. Finally, the conclusions for the alloys corrosion performance in acidic and basic solutions are provided.

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