scholarly journals The Tribological Property and Microstructure of Ni-Ti Coating Prepared by Electrodeposition and Heat Treatment

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Chufeng Sun ◽  
Yanbin Wang ◽  
Qiong Su ◽  
Zhiguang Guo ◽  
Lei Shi
Keyword(s):  
Heat Treatment ◽  
Intermetallic Compounds ◽  
Tribological Property ◽  
Friction And Wear ◽  
Xrd Analysis ◽  
Nitrogen Atmosphere ◽  
Strengthening Effect ◽  
X Ray Diffraction ◽  
Plating Bath ◽  
Before And After

Ni-Ti coatings were fabricated by the electrodeposition in a Ni plating bath containing Ti power and heat treatment in nitrogen atmosphere. The surface morphology and microstructure of the Ni-Ti coating before and after heat treatment were analyzed by means of scanning electron microscopy and X-ray diffraction. The friction and wear behaviors of two different coatings were evaluated on a ball-on-disk UMT-2MT test rig. It was found that the phase structure of Ni-Ti coating heated in nitrogen was much different from that of the as-deposited Ni-Ti coating. Namely, the new intermetallic compounds, including Ni3Ti, NiTi, and NiTi2, and TiN were detected in the coating after heat treatment by the XRD analysis and contributed to greatly increasing the hardness and tribological property of the Ni-Ti coating, owing to the strengthening effect of the hard intermetallic compounds and TiN phase. At the same time, a small amount of intermetallic compounds and TiN was transferred from the composite coating to the rubbing surface of the counterpart steel ball during the sliding, which also contributed to decreasing the friction coefficient and increasing the wear resistance.

Effects of Impregnating and Heat Treatment on the Oxidation and Thermal Shock Properties of Pressureless Sintered SiC/Graphite Composites

2012 ◽  
Vol 724 ◽  
pp. 311-314
Author(s):  
Wan Li Yang ◽  
Zhong Qi Shi ◽  
Zhi Hao Jin ◽  
Guan Jun Qiao
Keyword(s):  
Heat Treatment ◽  
Thermal Shock ◽  
Oxidation Resistance ◽  
Vickers Hardness ◽  
Volume Fraction ◽  
Nitrogen Atmosphere ◽  
Silica Sol ◽  
X Ray Diffraction ◽  
Heat Treated ◽  
Before And After

SiC/0~20% graphite (volume fraction) composites were successfully fabricated by pressureless sintering at 1700 °C for 2 h in nitrogen atmosphere. The impregnating and heat treatment process for the samples with silica sol/phenolic impregnant was carried out at 1450 °C for 2 h in nitrogen atmosphere. The Vickers hardness, oxidation resistance and thermal shock property of the composites before and after treatment were tested, and the microstructure and phase composition were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results shown that the Vickers hardness of SiC/20% graphite was increased from 3.35 GPa to 4.90 GPa by heat treatment, and the oxidation resistance and thermal shock property of the heat treated samples were also improved significantly. The SEM and XRD results revealed that the formation of new SiC particles by the reaction of silica sol and phenolic was the main reason for the mechanical properties improvements.

scholarly journals Heat Treatment-Induced Microstructure and Property Evolution of Mg/Al Intermetallic Compound Coatings Prepared by Al Electrodeposition on Mg Alloy from Molten Salt Electrolytes

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1407
Author(s):  
Tianyu Yao ◽  
Kui Wang ◽  
Haiyan Yang ◽  
Haiyan Jiang ◽  
Jie Wei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Mg Alloy ◽  
X Ray Diffraction ◽  
Electron Backscattered Diffraction ◽  
Alloy Matrix ◽  
Comprehensive Properties ◽  
Compound Coatings ◽  
Compound Coating

A method of forming an Mg/Al intermetallic compound coating enriched with Mg17Al12 and Mg2Al3 was developed by heat treatment of electrodeposition Al coatings on Mg alloy at 350 °C. The composition of the Mg/Al intermetallic compounds could be tuned by changing the thickness of the Zn immersion layer. The morphology and composition of the Mg/Al intermetallic compound coatings were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron backscattered diffraction (EBSD). Nanomechanical properties were investigated via nano-hardness (nHV) and the elastic modulus (EIT), and the corrosion behavior was studied through hydrogen evolution and potentiodynamic (PD) polarization. The compact and uniform Al coating was electrodeposited on the Zn-immersed AZ91D substrate. After heat treatment, Mg2Al3 and Mg17Al12 phases formed, and as the thickness of the Zn layer increased from 0.2 to 1.8 μm, the ratio of Mg2Al3 and Mg17Al12 varied from 1:1 to 4:1. The nano-hardness increased to 2.4 ± 0.5 GPa and further improved to 3.5 ± 0.1 GPa. The Mg/Al intermetallic compound coating exhibited excellent corrosion resistance and had a prominent effect on the protection of the Mg alloy matrix. The control over the ratio of intermetallic compounds by varying the thickness of the Zn immersion layer can be an effective approach to achieve the optimal comprehensive performance. As the Zn immersion time was 4 min, the obtained intermetallic compounds had relatively excellent comprehensive properties.

scholarly journals Ostrich eggshell as calcium source for the synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc

Cerâmica ◽  
2016 ◽  
Vol 62 (364) ◽  
pp. 386-391 ◽  
Author(s):  
J. R. M. Ferreira ◽  
L. H. L. Louro ◽  
A. M. Costa ◽  
J. B. de Campos ◽  
M. H. Prado da Silva
Keyword(s):  
Xrd Analysis ◽  
Quantitative Chemical Analysis ◽  
X Ray Diffraction ◽  
Spectroscopy Technique ◽  
X Ray ◽  
Heat Treated ◽  
Before And After ◽  
Calcium Source ◽  
The Fourier Transform ◽  
Ostrich Eggshell

Abstract In the present study, hydroxyapatite and Zn-substituted hydroxyapatite powders were synthesized using ostrich eggshell as a calcium source. The samples were analyzed by scanning electron microscopy with field emission gun, and X-ray diffraction (XRD) to identify the present phases, and X-ray fluorescence spectroscopy for quantitative chemical analysis of the synthesized and heat treated powders. The Fourier transform infrared spectroscopy technique was used before and after heat treatments at 700, 900 and 1100 °C in order to identify the functional groups present, as an additional technique to the XRD analysis. The results presented in this study represent a promising method for synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc, since the results showed no undesirable phases or impurities in the produced powders. It was observed that Zn-substituted hydroxyapatite showed higher thermal stability, when compared to pure hydroxyapatite.

Synthesis of Ultra-Thin Superhydrophilic Titanium Oxide Film and its Effects on the Capillary of Microchannels

2010 ◽  
Author(s):  
Min Zhang ◽  
Bo Zhang ◽  
Tianhong Cui
Keyword(s):  
Titanium Oxide ◽  
Sol Gel ◽  
Nitrogen Atmosphere ◽  
Tio2 Films ◽  
Titanium Tetraisopropoxide ◽  
X Ray Diffraction ◽  
Before And After ◽  
Potential Applications ◽  
Temperature Surface

Ultra-thin superhydrophilic titanium oxide films were fabricated on silicon microchannels by an in situ reaction sol-gel method using titanium tetraisopropoxide as a starting material.. By changing the concentration of water in ethanol and reaction time, the thickness of synthesized TiO2 films can be controlled from around 10 nm to 80 nm. The contact angle of as-synthesized TiO2 films on flat silicon is around 20° and can be further decreased to zero by calcination at 700 °C in nitrogen atmosphere. X-ray diffraction spectra show the microstructure of the TiO2 films changed gradually from amorphous to anatase with the increase of calcination temperature. Surface morphology of the film before and after calcination also shows that a smoother coating with crystal structure was obtained by heat treatment. The flow velocity in the TiO2 coated channel reached around 0.03 m/s, almost ten times of that in PDDA/PSS coated channel and 4 times of that in SiO2 coated one. The ultra-thin superhydrophilic TiO2 films fabricated by this method show the ability to strongly increase the wettability of microchannels without affecting the morphology of the sidewall of the channels, indicating potential applications to biomolecule analysis and surface tension driven microfluidic systems.

scholarly journals Microstructure Evolution and Performance Improvement of Hypereutectic Al–Mg2Si Metallic Composite with Ca or Sb

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2714
Author(s):  
Min Zuo ◽  
Boda Ren ◽  
Zihan Xia ◽  
Wenwen Ma ◽  
Yidan Lv ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nucleation Behavior ◽  
X Ray ◽  
Primary Mg2si ◽  
Before And After ◽  
And Performance ◽  
Hardness Values

In this article, the modification effects on Al–Mg2Si before and after heat treatment were investigated with Ca, Sb, and (Ca + Sb). In comparison with single Ca or Sb, the samples with composition modifiers (Ca + Sb) had the optimal microstructure. The sample with a molar ratio for Ca-to-Sb of 1:1 obtained relatively higher properties, for which the Brinell hardness values before and after heat treatment were remarkably increased by 31.74% and 28.93% in comparison with bare alloy. According to differential scanning calorimetry analysis (DSC), it was found that the nucleation behavior of the primary Mg2Si phase could be significantly improved by using chemical modifiers. Some white particles were found to be embedded in the center of Mg2Si phases, which were deduced to be Ca5Sb3 through X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) analyses. Furthermore, Ca5Sb3 articles possess a rather low mismatch degree with Mg2Si particles based on Phase Transformation Crystallography Lab software (PTCLab) calculation, meaning that the efficient nucleation capability of Ca5Sb3 for Mg2Si particles could be estimated.

X-Ray Diffraction Studies on the Titanium-Nickel System

1962 ◽  
Vol 6 ◽  
pp. 74-84
Author(s):  
John V. Gilfrich
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Stoichiometric Composition ◽  
Physical Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Property Data ◽  
Before And After ◽  
Titanium Nickel ◽  
Physical Property Data

AbstractX-ray diffraction studies were made on the Ti–Ni system around the stoichiometric composition of the intermetallic compound TiNi to clarify some confusion which has existed about the phase diagram in this region, and to explain some anomalies in the physical properties of this material. Wrought and cast samples were examined at room temperature both before and after heat treatment and at temperatures both above and below ambient. The compound TiNi does exist at room temperature. The phase purity of the particular sample was found to be greatly affected by such factors as minor variations in composition, heat treatment, and method of sample preparation. Some confirming metallographlc and physical property data will also be presented.

Effects of Ammonium Hexafluorosilicate Concentration on Crystallinity of Hydroxyapatite Powder and Enamel

2012 ◽  
Vol 529-530 ◽  
pp. 526-530 ◽  
Author(s):  
Toshiyuki Suge ◽  
Takashi Matsuo
Keyword(s):  
Xrd Analysis ◽  
Enamel Surface ◽  
Angular Width ◽  
X Ray Diffraction ◽  
Tooth Discoloration ◽  
Ammonium Hexafluorosilicate ◽  
Hydroxyapatite Powder ◽  
Human Enamel ◽  
Demineralized Enamel ◽  
Before And After

Ammonium hexafluorosilicate [SiF: (NH4)2SiF6] solution was prepared in order to overcome the tooth discoloration caused by diamine silver fluoride [AgF: (NH3)2AgF] application. However, it is still unclear how the concentration of SiF solution affects the crystallinity of enamel. The aim of this study was to evaluate the effects of changing concentrations of SiF solution on the crystallinity of hydroxyapatite powder and structure of human enamel. Hydroxyapatite powder was treated with several concentrations of SiF solution (from 10 to 19,400 ppm) for five min. The crystallinity of hydroxyapatite powder before and after SiF treatment was then measured by powder X-ray diffraction (XRD) analysis. The angular width (β) of the 002 diffraction peak was measured at 1/2 the height of the maximum intensity. Also, enamel specimens were prepared from a human extracted tooth. Several concentrations of SiF solution were applied to polished or phosphoric acid etched enamel specimens. The enamel surface was then observed using scanning electron microscopy (SEM). XRD peaks became sharper after SiF treatment indicating that the crystallinity of apatite powder was increased. The 1/β value was increased from 2.8±0.1 to 4.3±0.1 after treatment with 1,000 ppm SiF solution. The amount of CaF2 formed in hydroxyapatite powder was gradually increased with increasing concentrations of SiF solution. The XRD pattern was consistent with CaF2 in case of over 9,000 ppm SiF solution. SEM photographs demonstrated that exposed enamel rods with acid etching were filled with CaF2-like precipitate after SiF treatment regardless of the concentration of SiF solution. It was concluded that SiF treatment increased the crystallinity of apatite powder and repaired the demineralized enamel surface with the formation of CaF2 or CaF2-like precipitate, and thus, SiF treatment would be useful for the prevention of dental caries.

Reduced electrical resistivity of reaction-sintered SiC by nitrogen doping

2008 ◽  
Vol 23 (4) ◽  
pp. 1020-1025 ◽  
Author(s):  
Young-Sam Jeon ◽  
Hyunho Shin ◽  
Young-Hyun Lee ◽  
Sang-Won Kang
Keyword(s):  
Heat Treatment ◽  
Electrical Resistivity ◽  
Photoelectron Spectroscopy ◽  
Nitrogen Doping ◽  
Nitrogen Atmosphere ◽  
X Ray Diffraction ◽  
Post Heat Treatment ◽  
X Ray ◽  
Sic Particles ◽  
Transmission Electron

A post heat treatment of reaction-sintered SiC at 1700 °C in nitrogen atmosphere significantly reduced electrical resistivity. A trace of insulating Si3N4 phase was detected via nitrogen heat treatment in high-resolution transmission electron microscopy observation; however, based on x-ray photoelectron spectroscopy, the evidence of nitrogen doping into SiC lattice has been claimed as the mechanism to the decreased resistivity. The increase of the total volume of SiC was apparent in x-ray diffraction during the nitrogen heat treatment, which was interpreted to stem from the growth of the nitrogen-doped intergranular SiC particles and surface doping of the primary SiC to reduce the contact resistance between the primary SiC particles.

Reaction Process of Al-TiO2-C-Ti-Fe Multiphase System during Combustion Synthesis

2007 ◽  
Vol 336-338 ◽  
pp. 2340-2343 ◽  
Author(s):  
Song He Meng ◽  
Xing Hong Zhang ◽  
Wei Feng Zhang
Keyword(s):  
Intermetallic Compounds ◽  
Xrd Analysis ◽  
Reaction Process ◽  
Multiphase System ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Reaction Characteristics ◽  
Lower Temperature ◽  
Kinetics Of

The reaction process and kinetics of Al-TiO2-C-Ti-Fe system were investigated by differential scanning calorimetry (DSC) analysis, X-ray diffraction (XRD) analysis and scanning electron microscope (SEM). In order to obtain the information of reaction process for complicated system, the reaction characteristics of Al-TiO2, Al-TiO2-C and Al-TiO2-C-Ti systems are explored firstly. The results show that the reaction process varies with temperature in Al-TiO2-C-Ti-Fe system. At the lower temperature, the dominating reaction in Al-TiO2-C-Ti-Fe system is that between Al and Ti, Al and Fe, and so TiAlx, FeAlx, and Ti2Fe intermetallic compounds form. With the temperature increasing, the intermetallic compounds are decomposed. Then the decomposed Ti and Al react with C and TiO2 respectively and the stable TiC, Al2O3 and Fe three phases form in the final product.

scholarly journals Influence of Heat Treatment on the Mechanical Properties of Ni Films on 430 Stainless Steel Substrate

2017 ◽  
Vol 36 (8) ◽  
pp. 855-861
Author(s):  
Yong Pan ◽  
Junwei Cui ◽  
Weixin Lei ◽  
Jie Zhou ◽  
Zengsheng Ma
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
X Ray Diffraction ◽  
Before And After ◽  
430 Stainless Steel ◽  
Different Temperatures ◽  
Texture Orientation

AbstractEffects of heat treatment on the mechanical properties of Ni films on 430 stainless steel substrate were investigated. The Ni films were annealed at heat treatment temperatures ranging from 0 °C to 800 °C for 2 h. The surface morphology, composition, and texture orientation of Ni films were studied by scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction. The load–indentation depth curves of Ni films before and after heat treatment were measured by using nanoindentation method. In conjunction with finite element modeling and dimensional analysis, the stress–strain relationships of Ni films on 430 stainless steel substrate at different temperatures are successfully obtained by using a power-law hardening model.

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