scholarly journals Thermal Behavior of Single-Crystal Diamonds Catalyzed by Titanium Alloy at Elevated Temperature

2020 ◽  
Vol 10 (13) ◽  
pp. 4651
Author(s):  
Pengyu Hou ◽  
Ming Zhou ◽  
Haijun Zhang
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Tool Material ◽  
Alloy Sheet ◽  
Machine Material ◽  
X Ray ◽  
Single Crystal Diamond

Single-crystal diamonds are considered as the best tool material for ultra-precision machining. However, due to its low thermal conductivity, small elastic modulus and strong chemical activity, titanium alloy has poor machinability and is a typically difficult-to-machine material. Excessive tool wear prevents diamonds from cutting titanium alloy. This study conducts a series of thermal analytic experiments under conditions of different gas atmospheres in order to research the details of thermochemical wear of diamonds catalyzed by titanium alloy at elevated temperatures. Raman scattering analysis was performed to identify the transformation of the diamond crystal structure. The change in chemical composition of the work material was detected be means of energy dispersive X-ray analysis. X-ray photoelectron spectroscopy was used to confirm the resultant interfacial thermochemical reactions. The results of the study reveal the diffusion law of the single-crystal diamond under the action of titanium in the argon and air environment. From the experimental results, the product of the chemical reaction corresponding to the interface between the diamond and the titanium alloy sheet could be found. The research results provide a theoretical basis for elucidating the wear mechanism of diamond tools in the titanium alloy cutting process and for exploring the measures to suppress tool wear.

Cutting Performance of Cemented Carbide Using Single Crystal Diamond for Tool Material in Die and Mold Manufacturing

2013 ◽  
Vol 404 ◽  
pp. 56-61
Author(s):  
Kawasaki Kazumasa ◽  
Fukazawa Katsuya ◽  
Higuchi Satoru
Keyword(s):  
Tool Wear ◽  
Single Crystal ◽  
Ultrafine Particles ◽  
Tool Material ◽  
Cutting Performance ◽  
Cemented Carbide ◽  
Depth Of Cut ◽  
Surface Form ◽  
Single Crystal Diamond ◽  
Die And Mold

In this paper, the cutting performance of cemented carbide with ultrafine particles using single crystal diamond for tool material in die and mold manufacturing is investigated. The flat work is done using spiral for tool pass. The flat work is divided into small area and middle area. The spiral pitch in addition to depth of cut is changed in flat work. The tool wear is also estimated from form deviation by measuring surface form before and after machining. These results showed that ductile mode cutting was possible and the tool wear could be estimated from surface form. The tool wear was large in proportion to both the depth of cut and cutting length.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

On The Optimized Nucleation of Near-Single-Crystal Cvd Diamond Film

1995 ◽  
Vol 416 ◽  
Author(s):  
L. C. Chen ◽  
C. C. Juan ◽  
J. Y. Wu ◽  
K. H. Chen ◽  
J. W. Teng
Keyword(s):  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Morphological Evolution ◽  
Present Report ◽  
Ex Situ ◽  
Nucleation Density ◽  
Induced Current ◽  
Current Time ◽  
Single Crystal Diamond

ABSTRACTNear-single-crystal diamond films have been obtained in a number of laboratories recently. The optimization of nucleation density by using a bias-enhanced nucleation (BEN) method is believed to be a critical step. However, the condition of optimized nucleation has never been clearly delineated. In the present report, a novel quantitative technique was established to monitor the nucleation of diamond in-situ. Specifically, the induced current was measured as a function of nucleation time during BEN. The timedependence of induced current was studied under various methane concentrations as well as substrate temperatures. The optimized nucleation condition can be unambiguously determined from the current-time plot. Besides the in-situ current probe, ex-situ x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were also used to investigate the chemical and morphological evolution. Characteristic XPS and AFM features of optimized nucleation is discussed.

Development of Diamond-Based X-ray Detection for High Flux Beamline Diagnostics

2009 ◽  
Vol 1203 ◽  
Author(s):  
Jen Bohon ◽  
John Smedley ◽  
Erik M. Muller ◽  
Jeffrey W. Keister
Keyword(s):  
Single Crystal ◽  
Linear Response ◽  
Voltage Dependence ◽  
Cvd Diamond ◽  
High Flux ◽  
National Synchrotron Light Source ◽  
X Ray ◽  
Single Crystal Diamond ◽  
Synchrotron Light ◽  
Pulse Structure

AbstractHigh quality single crystal and polycrystalline CVD diamond detectors with platinum contacts have been tested at the white beam X28C beamline at the National Synchrotron Light Source under high-flux conditions. The voltage dependence of these devices has been measured under DC and pulsed-bias conditions, establishing the presence or absence of photoconductive gain in each device. Linear response has been achieved over eleven orders of magnitude when combined with previous low flux studies. Temporal measurements with single crystal diamond detectors have resolved the ns scale pulse structure of the NSLS.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

scholarly journals Ferromagnetic Properties of N-Doped and Undoped TiO2 Rutile Single-Crystal Wafers with Addition of Tungsten Trioxide

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1934 ◽  
Author(s):  
Jing Xu ◽  
Haiying Wang ◽  
Zhongpo Zhou ◽  
Zhaorui Zou
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Saturation Magnetization ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Tio2 Surface ◽  
Doped Tio2 ◽  
X Ray ◽  
N Doping ◽  
Tio2 Rutile

In this work, undoped, N-doped, WO3-loaded undoped, and WO3-loaded with N-doped TiO2 rutile single-crystal wafers were fabricated by direct current (DC) magnetron sputtering. N-doping into TiO2 and WO3 loading onto TiO2 surface were used to increase and decrease oxygen vacancies. Various measurements were conducted to analyze the structural and magnetic properties of the samples. X-ray diffraction results showed that the N-doping and WO3 loading did not change the phase of all samples. X-ray photoelectron spectroscopy results revealed that W element loaded onto rutile single-crystal wafers existed in the form of WO3. UV-Vis spectrometer results showed that the absorption edge of WO3-loaded undoped and WO3-loaded with N-doped TiO2 rutile single-crystal wafers had red shift, resulting in a slight decrease in the corresponding band gap. Photoluminescence spectra indicated that oxygen vacancies existed in all samples due to the postannealing atmosphere, and oxygen vacancies density increased with N-doping, while decreasing with WO3 loading onto TiO2 surface. The magnetic properties of the samples were investigated, and the saturation magnetization values were in the order N-doped > WO3-loaded with N-doped > undoped > WO3-loaded undoped rutile single-crystal wafers, which was the same order as the oxygen vacancy densities of these samples. N-doping improved the saturation magnetization values, while WO3-loaded decreased the saturation magnetization values. This paper reveals that the magnetic properties of WO3-loaded with N-doped rutile single-crystal wafers originate from oxygen vacancies.

scholarly journals X-Ray Beam Position Monitor Based on a Single Crystal Diamond Performing Bunch by Bunch Detection

2013 ◽  
Vol 425 (21) ◽  
pp. 212001 ◽  
Author(s):  
M Di Fraia ◽  
M Antonelli ◽  
A Tallaire ◽  
J Achard ◽  
S Carrato ◽  
...  
Keyword(s):  
Single Crystal ◽  
Beam Position Monitor ◽  
Beam Position ◽  
X Ray ◽  
Single Crystal Diamond

scholarly journals The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

2021 ◽  
Vol 12 ◽  
pp. 1173-1186
Author(s):  
Markus Gehring ◽  
Tobias Kutsch ◽  
Osmane Camara ◽  
Alexandre Merlen ◽  
Hermann Tempel ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Elevated Temperatures ◽  
Current Collector ◽  
Alkaline Media ◽  
Emission Spectrometry ◽  
Free Standing ◽  
X Ray ◽  
Turbostratic Carbon ◽  
Current Densities

An innovative approach for the design of air electrodes for metal–air batteries are free-standing scaffolds made of electrospun polyacrylonitrile fibres. In this study, cobalt-decorated fibres are prepared, and the influence of carbonisation temperature on the resulting particle decoration, as well as on fibre structure and morphology is discussed. Scanning electron microscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, elemental analysis, and inductively coupled plasma optical emission spectrometry are used for characterisation. The modified fibre system is compared to a benchmark system without cobalt additives. Cobalt is known to catalyse the formation of graphite in carbonaceous materials at elevated temperatures. As a result of cobalt migration in the material the resulting overall morphology is that of turbostratic carbon. Nitrogen removal and nitrogen-type distribution are enhanced by the cobalt additives. At lower carbonisation temperatures cobalt is distributed over the surface of the fibres, whereas at high carbonisation temperatures it forms particles with diameters up to 300 nm. Free-standing, current-collector-free electrodes assembled from carbonised cobalt-decorated fibre mats display promising performance for the oxygen reduction reaction in aqueous alkaline media. High current densities at an overpotential of 100 mV and low overpotentials at current densities of 333 μA·cm−2 were found for all electrodes made from cobalt-decorated fibre mats carbonised at temperatures between 800 and 1000 °C.

Linear parabolic single-crystal diamond refractive lenses for synchrotron X-ray sources

2017 ◽  
Vol 24 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Sergey Terentyev ◽  
Maxim Polikarpov ◽  
Irina Snigireva ◽  
Marco Di Michiel ◽  
Sergey Zholudev ◽  
...  
Keyword(s):  
Single Crystal ◽  
Focal Spot ◽  
Synthetic Diamond ◽  
Picosecond Laser ◽  
Radius Of Curvature ◽  
High Quality ◽  
X Ray ◽  
Single Crystal Diamond ◽  
Refractive Lens ◽  
Focusing Properties

Linear parabolic diamond refractive lenses are presented, designed to withstand high thermal and radiation loads coming from upgraded accelerator X-ray sources. Lenses were manufactured by picosecond laser treatment of a high-quality single-crystal synthetic diamond. Twelve lenses with radius of curvature at parabola apex R = 200 µm, geometrical aperture A = 900 µm and length L = 1.5 mm were stacked as a compound refractive lens and tested at the ESRF ID06 beamline. A focal spot of size 2.2 µm and a gain of 20 were measured at 8 keV. The lens profile and surface quality were estimated by grating interferometry and X-ray radiography. In addition, the influence of X-ray glitches on the focusing properties of the compound refractive lens were studied.

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