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1

Wear evaluation of CVD diamond coated high-performance drilling tools for machining of carbon fiber reinforced plastics (CFRP)

Uhlmann Eckart, Reimers Walter, Hinzmann Daniel, Christiansen Gerret, Böttcher Katrin

Journal of Machine Engineering

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2020

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Vol. 20, No. 2

104--113

EN

The application of carbon fiber reinforced plastics (CFRP) as lightweight construction material in aerospace industry is based on the favorable weight-to-strength ratio. But the inherent material properties pose great challenges for the tool- as well as the manufacturing industry. In terms of economic industrial production processes, the quality of machined workpieces exhibits poor reproducibility combined with high tool wear. For this purpose, high-performance drilling tools with different CVD diamond coatings and carbide substrates with varying binder content were tested and analyzed in order to assess coating adhesion and workpiece quality. Due to a reduction of cobalt binder within the tungsten carbide-based tool substrates, an increase of tool performance regarding borehole quantity until coating delamination is demonstrated. While the reduction of tool wear on the rake face of the drilling tools can be correlated with the cutting tool performance, the online monitoring of cutting forces does not explicitly identify damaged cutting tools during machining.

2

Chemically vapor deposited diamond films as dosimetric material for potential clinical applications

Kabacińska R., Winiecki J., Przegiętka K., Szybowicz M., Fabisiak K., Paprocki K.

Materials Science Poland

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2017

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Vol. 35, No. 4

702--706

EN

Thermally stimulated luminescence (TL), cathodoluminescence (CL) and Raman spectroscopy of CVD diamond films grown on silicon substrates have been studied in order to obtain information on defects created during the growth, which induce the levels within the gap. TL between 300 K and 700 K, and CL from 200 nm to 1200 nm have been teasured. The glow curves show a peak located around 610 K with different intensities, depending on the sample thickness, associated with a trap of energy, equal to 0.83 eV and with attempt-to-escape-time of the order of 108 s-1. Broad CL bands observed at 428±1 nm (2.90 ±0.01 eV) and 500±1 nm (2.47±0.004 eV) are attributed to closely spaced and widely separated donor-acceptor (D-A) pairs, respectively. The TL and CL results were correlated with diamond quality estimated from Raman spectroscopy measurements.

3

Cyclic voltammetry and impedance studies of undoped diamond films

Mosińska L., Kowalska M., Popielarski P., Fabisiak K., Paprocki K., Szybowicz M., Wrzyszczynski A., Zhusupkalieva G. K.

Materials Science Poland

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2013

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Vol. 31, No. 1

146-150

EN

The undoped, polycrystalline diamond films were deposited on tungsten wire substrates by hot filament chemical vapor deposition (HF CVD), using a precursor gas mixture of methanol with excess of hydrogen. The morphology and quality of the as-deposited films were monitored by scanning electron microscopy (SEM) and Raman spectroscopy. The surface morphology analyzed by SEM resembles a continuous and well faceted diamond film. Raman results showed essential differences in qualities of diamond films grown at different hydrocarbon concentrations. The electrochemical properties of diamond electrodes were examined with cyclic voltammetry (CV) and the electrochemical impedance spectroscopy (EIS). The CV experiments revealed a large chemical window (>~4.3 V) of undoped diamond. Analysis of the ferrocyanide-ferricyanide couple at a diamond electrode suggests some extent of electrochemical quasi-reversibility, but the rates of charge transfer across the diamond substrate interface vary with diamond quality.

4

Simulation of acoustic wave devices using Matlab

Mendes J., Fernandes M., Mukherjee D.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 1a

155-158

EN

A review of the principles and applications of surface acoustic wave (SAW) devices is given. An implementation of a design method for SAW devices using MATLAB is described. Results of a comparison between the proposed simulation technique and experimental test results are presented.

PL

Przedstawiono zasadę działania i wykorzystanie urządzęń typu SAW (urządzenia z akustyczną fala powierzchniową). Zaproponowano metody projektowania murządzęń z wykorzystaniem platformy MATLAB.

5

Fabrication and electrochemical properties of diamond layers grown on tungsten wire by HF CVD method

Torz-Piotrowska R., Uniszkiewicz C., Szreiber M., Wrzyszczynski A., Staryga E., Runka T., Kasprowicz D.

Optica Applicata

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2009

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Vol. 39, nr 4

951-957

EN

Un-doped polycrystalline diamond thin films have been grown on tungsten substrates by hot filament chemical vapor deposition (HF CVD) using a hydrogen and methanol vapor mixture. Diamond films have been analyzed by Raman spectroscopy and scanning electron microscopy (SEM). Cyclic voltammetric behavior of diamond films of different quality and morphology has been studied in acetonitryle with (n-Bu)4NClO4 and in 0.1 M KCl aqueous solutions. Preliminary cyclic voltammetry (CV) measurements showed that our electrodes have a wide potential range over which negligible background response current is observed. The potential windows depend on the type of solvent. In the case of water solution the decomposition of water occurs electrochemically and evolves O2 during positive (anodic) polarization and H2evolution during negative (cathodic) polarization. The electrochemical properties of diamond electrodes have been evaluated by performing cyclic voltammetry measurements in [Fe(CN)6]3-/4- with 0.1 M KCl. The electrode demonstrates reversible kinetics during electrochemical analysis.

6

Zmiany powierzchniowej przewodności elektrycznej diamentu CVD spowodowane chemisorpcją wodoru

Kulesza S.

Karbo

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2003

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Nr 2

78-81

PL

Zbadano niezwykły charakter wysokiej elektrycznej przewodności powierzchniowej w uwodornionym diamencie oraz możliwe przyczyny jej powstawania. Wykonane pomiary pokazały, że opór powierzchniowy diamentu pokrytego warstwą adsorbatu może się. w sposób odwracalny zmieniać o kilka rzędów wielkości. Uzyskane wyniki pozwoliły wydedukować przypuszczalne ścieżki reakcji chemicznych odpowiedzialnych za te zmiany, co w dalszej perspektywie doprowadziło do skorygowania dotychczasowego modelu struktury pokrycia adsorpcyjnego na powierzchni diamentu. Odpowiednie wykorzystanie procesów adsorpcji i desorpcji gazów daje tym samym możliwość budowy powierzchniowych przyrządów elektronicznych, poszerzających zakres dotychczasowych zastosowań diamentu.

EN

The paper deals with unusual character of the high surface conductivity in hydrogenated diamond as compared to other semiconductors, and its strange origin. Electrical measurements of adsorbate-covered polycry-stalline diamond were performed indicating that surface resistance could be reversibly changed within orders of magnitude. On that basis hypothetical reaction path is suggested and the previous model of highly conducting diamond surface is revised. Such a result points at an alternative way to realize the so-called „diamond electronics" taking advantage of controlled adsorption and desorption of gaseous species.