Characterization of Surface Composition and Microstructure of H21 Steel Implanted Using Masking Ti-Implantation

2011 ◽  
Vol 228-229 ◽  
pp. 130-134
Author(s):  
Jian Hua Yang ◽  
Song Li

Ti ions were implanted into H21 steel to improve the surface structure of oxides in H21 steel. The wear characteristics of the implanted steel was measured and compared to the performance of the un-implanted steel by a line-cutting apparatus and an optical interference microscope. The Ti concentration depth profile of the implanted steel was measured by Rutherford backscattering spectroscopy (RBS). The structure and composition of oxides were analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The results showed that the improved wear resistance of the implanted steel was mainly due to the structure and composition changes of the surface oxides after Ti ion implantation.

Author(s):  
S.Y. Hwang ◽  
B.G. Seong ◽  
M.C. Kim

Abstract To maintain surface roughness of process rolls in cold rolling steel plants, WC-Co coatings have been known to be effective ones. In this study, a high pressure/high velocity oxygen fuel (HP/HVOF) process was used to obtain WC-Co coatings. To get the best quality of coatings, WC-Co coatings are sprayed with numerous powders made by various processes. These powders include agglomerated sintered powders, fused-crushed powders, extra high carbon WC-Co powders and (W2C, WC)-Co powders. After spraying, properties of coatings such as hardness, wear resistance. X-ray diffraction, and microstructures were analyzed. For coatings produced by agglomerated-sintered powders, hardness of the coating increased as power levels and the number of passes were increased. In case of the coatings produced by fused-crushed powders, a very low deposition rate was obtained due to a low flowablity of the powders. In addition, the WC-Co coatings sprayed with extra carbon content of WC-Co did not show improved hardness and wear resistance. Also, some decomposition of WC was observed in the coating. Finally, the coatings produced by (W2C, WC)-Co powders produced higher hardness and lower wear resistance coating.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
YiChao Yan ◽  
Wei Shi ◽  
HongChuan Jiang ◽  
Jie Xiong ◽  
WanLi Zhang ◽  
...  

The redox reaction between Al and metallic oxide has its advantage compared with intermetallic reaction and Al/NiO nanomutlilayers are a promising candidate for enhancing the performance of energetic igniter. Al/NiO nanomutlilayers with different modulation periods are prepared on alumina substrate by direct current (DC) magnetron sputtering. The thicknesses of each period are 250 nm, 500 nm, 750 nm, 1000 nm, and 1500 nm, respectively, and the total thickness is 3 μm. The X-ray diffraction (XRD) and scanning electron microscope (SEM) results of the as-deposited Al/NiO nanomutlilayers show that the NiO films are amorphous and the layered structures are clearly distinguished. The X-ray photoelectron spectroscopy (XPS) demonstrates that the thickness of Al2O3increases on the side of Al monolayer after annealing at 450°C. The thermal diffusion time becomes greater significantly as the amount of thermal boundary conductance across the interfaces increases with relatively smaller modulation period. Differential scanning calorimeter (DSC) curve suggests that the energy release per unit mass is below the theoretical heat of the reaction due to the nonstoichiometric ratio between Al and NiO and the presence of impurities.


2002 ◽  
Vol 57 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Gülsün Gökağaç ◽  
Brendan J. Kennedy

11% Pt/C, 10% Pt + 1%Os/C, 9% Pt + 2%Os/C, 8% Pt + 3%Os/C, 7% Pt + 4%Os/C, 6% Pt + 5%Os/C and 5%Pt + 6% Os/C catalysts have been prepared for methanol oxidation reaction. Transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and cyclic voltammetry have been used to understand the nature of the species present in these catalysts. 7% Pt + 4% Os/C was the most active catalyst, while 8% Pt + 3% Os/C was the least active one. It is found that the metal particle size and distribution on the carbon support, the surface composition and the oxidation states of the metal particles, the metal-metal and metal support interactions are important parameters to define the activity of the catalyst.


2013 ◽  
Vol 873 ◽  
pp. 152-157
Author(s):  
Long Long Chen ◽  
Jun Ming Li ◽  
Xiao Min Gong ◽  
Jian Li

Using a chemically induced transition in an FeCl2 solution, γ-Fe2O3 nanoparticles can be prepared from an amorphous precursor composed of FeOOH and Mg (OH)2. Surface modification by adding ZnCl2 during liquid-phase synthesis was attempted. The magnetization, morphology, crystal structure, and chemical species of as-prepared samples were characterized by vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray energy-dispersive spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the surface of the γ-Fe2O3 nanoparticles can be modified by adding ZnCl2 to form composite nanoparticles with a γ-Fe2O3/ZnFe2O4 ferrite core coated with Zn (OH)2 and absorbed FeCl36H2O; this modification can be enhanced by additional NaOH.


2020 ◽  
Author(s):  
Sahar. Mokhtari ◽  
Anthony.W. Wren

AbstractThis study addresses issues with currently used bone adhesives, by producing novel glass based skeletal adhesives through modification of the base glass composition to include copper (Cu) and by characterizing each glass with respect to structural changes. Bioactive glasses have found applications in fields such as orthopedics and dentistry, where they have been utilized for the restoration of bone and teeth. The present work outlines the formation of flexible organic-inorganic polyacrylic acid (PAA) – glass hybrids, commercial forms are known as glass ionomer cements (GICs). Initial stages of this research will involve characterization of the Cu-glasses, significant to evaluate the properties of the resulting adhesives. Scanning electron microscopy (SEM) of annealed Cu glasses indicates the presence of partial crystallization in the glass. The structural analysis of the glass using Raman suggests the formation of CuO nanocrystals on the surface. X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy (XPS) further confirmed the formation of crystalline CuO phases on the surface of the annealed Cu-glass. The setting reaction was studied using Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the Cu containing adhesives exhibited gel viscoelastic behavior and enhanced mechanical properties when compared to the control composition. Compression data indicated the Cu glass adhesives were efficient at energy dissipation due to the reversible interactions between CuO nano particles and PAA polymer chains.


2000 ◽  
Vol 15 (10) ◽  
pp. 2076-2079
Author(s):  
Chika Nozaki ◽  
Takashi Yamada ◽  
Kenji Tabata ◽  
Eiji Suzuki

Synthesis of a rutile-type lead-substituted tin oxide with (110) face was investigated. The characterization was performed by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, infrared spectroscopy, x-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller surface area measurements. The homogeneous rutile-type lead-substituted tin oxide was obtained until 4.1 mol% of tin was substituted with lead. The surface of obtained oxide had a homogeneously lead-substituted (110) face.


1999 ◽  
Vol 14 (5) ◽  
pp. 1782-1790 ◽  
Author(s):  
X. L. Dong ◽  
Z. D. Zhang ◽  
S. R. Jin ◽  
W. M. Sun ◽  
X. G. Zhao ◽  
...  

Ultrafine Fe–Ni(C) particles of various compositions were prepared by arc discharge synthesis in a methane atmosphere. The particles were characterized by x-ray diffraction, transmission electron microscopy, energy disperse spectroscopy, chemical analysis, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and magnetization measurement. The carbon atoms solubilizing at interstitial sites in γ–(Fe, Ni, C) solution particles have the effects of forming austenite structure and changing microstructures as well as magnetic properties. A carbon layer covers the surface of Fe–Ni(C) particles to form the nanocapsules and protect them from oxidization. The mechanism of forming Fe–Ni(C) nanocapsules in the methane atmosphere was analyzed.


2011 ◽  
Vol 183-185 ◽  
pp. 2254-2257
Author(s):  
Ying Wei Wang ◽  
Yu Fei Li ◽  
Pei Han Yang

Nonmetal (S, P) doped titania nanoparticles were synthesized by a one step hydrothermal method. These samples were calcined with different temperature, the sample exist in anatase phase has much higher photocatalytic activity for methylene blue (MB) degradation. The visible response and the higher UV activity of the different nonmetal doped TiO2make it possible to utilize solar energy efficiently to execute photocatalysis processes. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), etc. It can conclude the nonmetal doping TiO2proves to be more suitable to improve the photocatalytic performance.


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