| 1. |
- Berger, M, et al.
(author)
-
The multilayer effect in abrasion : optimising the combination of hard and tough phases
- 1999
-
In: Surface & Coatings Technology. - : ELSEVIER SCIENCE SA. - 0257-8972 .- 1879-3347. ; 116-119, s. 1138-1144
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Journal article (other academic/artistic)abstract
- In the present investigation it is shown that the wear resistance of multilayer PVD coatings, combining relatively soft but tough chromium (Cr) and harder but more brittle chromium nitride (CrN): exceeds that of both its phases. This striking exception to
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| 2. |
- Bexell, U., et al.
(author)
-
A tribological study of a novel pre-treatment with linseed oil bonded to mercaptosilane treated aluminium
- 2003
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 166:03-feb, s. 141-152
-
Journal article (peer-reviewed)abstract
- In sheet metal forming processes, lubricants are necessary in order to prevent galling, i.e. material transfer from the sheet metal to the tool surface and to control friction. Today, dry lubricants are increasingly being used for solving this problem. Among these, multifunctional coatings, often referred to as permanent coatings, normally based on organic resins, are lubricants which have the potential to increase the formability without additional lubrication, give corrosion protection, fingerprint and scratch resistance during handling and transport and finally, serve as a pre-treatment before painting. With increasing concern about the environment and human health it is important to develop new environmentally friendly pre-treatments in the surface engineering of metal substrates. This is mainly due to the toxic and carcinogenic properties of the chromium based surface pre-treatments frequently used in the industry. During the last decade, simple solution-dip silane based pre-treatments have emerged as promising candidates for the replacement of currently used pre-treatments of metals. A silane film can give good corrosion protection properties but is often too thin to prevent galling under a forming operation. A renewed interest for using vegetable oils in surface engineering has appeared lately due to several factors. Vegetable oils are renewable resources, modem technology can produce more well defined and pure oils, and the fatty acid content can be altered with modern crops development techniques. With the proper choice of silane pre-treatment of a metal surface, a vegetable oil can be coupled to the surface and give the desired lubrication properties. In this paper, aluminium sheets have been pre-treated with a mercapto silane after which a vegetable oil has been attached. The coupling between the silane and the oil was obtained through a photoinduced thiol-ene reaction using UV-radiation. The influence of different process parameters on the friction and wear behaviour was evaluated using modified scratch testing. Scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and contact angle measurements were used to characterise the as-deposited surface films and their tribological behaviour, i.e. failure mechanisms. The results obtained show that the unsaturated vegetable oil has reacted with the thiol groups via the thiol-ene reaction forming a surface film. Also, the results show that the thickness of the films is of importance for the tribological characteristics, i.e. a too thin layer (less than 25 A in the present work) results in high friction and severe adhesive wear. However, a thicker layer with enhanced load carrying capacity can be produced with a proper heat treatment of the deposited vegetable oil. Finally, the results show that thick (more than 200 Angstrom in the present work) silane films are sensitive to brittle fracture when exposed to a sliding contact.
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| 3. |
- Ehiasarian, A.P., et al.
(author)
-
High power pulsed magnetron sputtered CrNx films
- 2003
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 163-164, s. 267-272
-
Journal article (peer-reviewed)abstract
- Microstructure and macroscopic properties of droplet free CrN films deposited by the recently developed high power pulsed magnetron sputtering (HIPIMS) technique are presented. Magnetron glow discharges with peak power densities reaching 3000 W cm-2 were used to sputter Cr targets in both inert and reactive gas atmospheres. The flux arriving at the substrates consisted of neutrals and ions (approx. 70/30) of the sputtered metal and working gas atoms (Ar) with significantly elevated degree of ionization compared to conventional magnetron sputtering. The high-speed steel and stainless steel substrates were metal ion etched using a bias voltage of -1200 V prior to the deposition of CrN films. The film-to-substrate interfaces, observed by scanning transmission electron microscope cross-sections, were clean and contained no phases besides the film and substrate ones or recrystallized regions. CrN films were grown by reactive HIPIMS at floating potential reaching -160 V. Initial nucleation grains were large compared to conventional magnetron sputtered films, indicating a high adatom mobility in the present case. The films exhibited polycrystalline columnar growth morphology with evidence of renucleation. No intercolumnar voids were observed and the corrosion behavior of the film was superior to arc deposited CrNx. A high density of lattice defects was observed throughout the films due to the high floating potential. A residual compressive stress of 3 GPa and a hardness value of HK0.025=2600 were measured. A low friction coefficient of 0.4 and low wear rates against Al2O3 in these films are explained by the absence of droplets and voids known to contribute to extensive debris generation.
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| 4. |
- Eskner, M., et al.
(author)
-
Measurement of the ductile-to-brittle transition temperature in a nickel aluminide coating by a miniaturised disc bending test technique
- 2003
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 165:1, s. 71-80
-
Journal article (peer-reviewed)abstract
- Nickel aluminide coatings are often employed to enhance the corrosion and oxidation resistance of nickel base gas turbine blades and vanes, as the high near-surface content of Al increases the ability to form an Al2O3 protective scale. The ductility of the coating depends on the type of aluminisation process and Ni-base material. In order to prevent coating degradation during service it is important to assess the ductile-to-brittle transition temperature (DBTT) in ductility of the coating. To determine the DBTT a miniaturised disc bending test (MDBT) technique is used, where a biaxial tensile stress is applied to a disc specimen. The DBTT of a NiAl coating, applied by a high-activity aluminium pack cementation process to a polycrystalline Ni-base superalloy (IN738 LC), was evaluated using the MDBT technique between room temperature (RT) and 860 degreesC. Test results gave a DBTT in biaxial ductility of the coating of approximately 760 degreesC. Above 760 degreesC, a significant increase in ductility was noted. Fractographic examination showed that the coating fractures in a mainly transgranular mode at RT but in a predominately intergranular mode at elevated temperatures, even at temperatures above DBTT.
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| 5. |
- Gudmundsson, Jon Tomas, 1965-, et al.
(author)
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Spatial and temporal behavior of the plasma parameters in a pulsed magnetron discharge
- 2002
-
In: Surface and Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 161:2-3, s. 249-256
-
Journal article (peer-reviewed)abstract
- We demonstrate the evolution of the electron, energy distribution and the plasma parameters in a high-density plasma in a pulsed magnetron discharge. The high-density plasma is created by applying a high power pulse (1–2.4 MW) with pulse length 100 μs and repetition frequency of 50 Hz to a planar magnetron discharge. The spatial and temporal behavior of the plasma parameters are investigated using a Langmuir probe; the electron energy distribution function, the electron density and the average electron energy. The electron energy distribution function during and shortly after the pulse can be represented by a bi-Maxwellian distribution indicating two energy groups of electrons. Furthermore, we report on the variation of the plasma parameters and electron energy distribution function with gas pressure in the pressure range 0.5–20 mtorr. We report electron density as high as 4×1018 m−3 at 10 mtorr and 9 cm below the target in a pulsed discharge with average power 300 W. We estimate the traveling speed of the electron density peak along the axis of the discharge. The traveling speed decreases with increased gas pressure from 4×105 cm/s at 0.5 mtorr to 0.87×105 cm s−1 at 10 mtorr. The effective electron temperature peaks at the same time independent of position in the discharge, which indicates a burst of high energy electrons at the end of the pulse.
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| 6. |
- Gunnars, Jens, et al.
(author)
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Thermal stresses in diamond coatings and their influence on coating wear and failure
- 1996
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In: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 80:3, s. 303-312
-
Journal article (peer-reviewed)abstract
- Thermal stresses in diamond coatings deposited onto cemented carbide substrates are calculated using the finite element method. The thermo-elastic stress fields for some coating-substrate geometries are presented. The results are compared with experimental data on the tribological behaviour of diamond coatings. Residual stresses can explain many of the observed patterns of coating wear and failure. A model for the abrasive wear of brittle coatings under large compressive biaxial stresses is described. These stresses prevent cracks initiated at the surface to propagate towards the interface and may promote crack paths parallel to the interface, thus causing the formation of a smooth coating surface. Once the smooth appearance is reached it will become extremely hard to initiate and propagate cracks into the coating and consequently the wear rate becomes very low. Thus, large compressive residual stresses increase the already high wear resistance of diamond coatings. When diamond coatings are deposited onto substrate edges, intense concentrations of normal and shear stresses may lead to coating failure by interfacial spalling. These stresses are lowered by increasing the ratio r/h, where r is the edge radius and h is the coating thickness.
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| 7. |
- Hansbo, Anita, 1960-, et al.
(author)
-
Models for the simulation of spray deposition and robot motion optimization in thermal spraying of rotating objects
- 1999
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 122:2-3, s. 191-201
-
Journal article (peer-reviewed)abstract
- In this paper we consider methods to simulate deposit build-up in thermal spraying and to optimize the robot motion so as to obtain the desired layer thickness. We derive a simplified mathematical model for spray deposition on a rotating large object with a smooth, rotationally symmetric, curved surface, yet allowing varying spray distance and direction. Further, we discuss how to obtain and incorporate an empirically determined deposit rate model. In particular, the simplified spray deposition model is chosen to make possible a reasonably cheap method to approximate a deposit rate from the results of layer thickness measurements. We also propose an iterative method to obtain good initial values for robot feed optimization. Numerical examples are presented. © 1999 Elsevier Science S.A.
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| 8. |
- Hedenqvist, Mikael S., et al.
(author)
-
Barrier properties of SiOx-coated polymers : multi-layer modelling and effects of mechanical folding
- 2003
-
In: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 172:1, s. 7-12
-
Journal article (peer-reviewed)abstract
- The oxygen permeability properties of poly(ethylene terephthalate), low- and high-density polyethylenes and polypropylene coated with SiOx using cold plasma were studied. A previously developed computer model for the calculation of transport properties in laminates containing very different layer thickness was fitted to experimental permeability data to obtain the oxygen transport properties of the SiOx coating. For the first time, to the best of our knowledge, it was possible to obtain the oxygen diffusivity and solubility of a SiOx coating on a polymer substrate. The effects of folding the laminates through 90degrees on the permeability properties of the SiOx coating were also investigated. The surface roughness of the substrates was obtained by atomic force microscopy and the morphology of the laminate surfaces was analysed by scanning electron microscopy. The oxygen diffusivity and solubility of a 45-nm-thick SiOx coating deposited on a 4000-fold thicker polypropylene substrate were 5 x 10(-12) cm(2) s(-1) and 0.72 cm(2) (STP) cm(-3) atm(-1), respectively. The diffusivity was approximately four orders of magnitude lower than that of the polymer substrate and, surprisingly, the solubility was higher than that of the polypropylene film. A hypothesis to explain these results is that the coating contained voids and, according to the permeability time lag, these were not continuous through the coating. The oxygen permeability of the coating increased with increasing substrate surface roughness, and was consequently lowest for poly(ethylene terephthalate). The folding operation initiated cracks in the coating, and the resulting increase in oxygen permeability was greater in the rougher substrates.
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| 9. |
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| 10. |
- Hultman, Lars, 1960-, et al.
(author)
-
Mechanical and thermal stability of TiN/NbN superlattice thin films
- 2000
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 133-134, s. 227-233
-
Journal article (peer-reviewed)abstract
- High-temperature stability and mechanical deformation mechanisms of TiN/NbN superlattice structures have been investigated. Single-crystal TiN/NbN superlattices were deposited by reactive dual-cathode unbalanced magnetron sputtering in an Ar/N2 discharge onto MgO(001) substrates held at a temperature of 700 ░C. The thermal stability was studied by X-ray measurements of superlattice satellite peak intensity variation during and after annealing at up to 950 ░C. The apparent activation energy for metal interdiffusion in the TiN-NbN diffusion couple is temperature-dependent, with values ranging from 2.6 to 4.5 eV. Film hardness as measured by nanoindentation was observed to decrease during annealing, as the result of effective alloying of the nitride layers. TiN/NbN superlattices are ductile at room temperature and exhibit dislocation glide limited to within individual layers in scratching experiments.
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| 11. |
- Jansson, U, et al.
(author)
-
Low temperature epitaxial growth of metal carbides using fullerenes
- 2001
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 142-144, s. 817-822
-
Journal article (peer-reviewed)abstract
- Epitaxial transition metal carbides can be deposited at low temperatures by simultaneous evaporation of C60 and either metal e-beam evaporation or metal d.c. magnetron sputtering. Hitherto, epitaxial films of TiC, VC, NbC, MoC, W2C and WC have been deposited on MgO(100), MgO(111) and in some cases 6H- and 4H-SiC(0001). Epitaxial TiC films with a good quality have been deposited at temperatures as low as 100°C with metal sputtering, while somewhat higher temperatures (> 200°C) are required for the other metals. In general, the plasma-assisted process allows lower deposition temperatures than the co-evaporation process. Most carbides can be deposited in a wide range of compositions within their homogeneity ranges by a fine-tuning of the Me/C60 flux. However, the results suggest that the formation of free surface carbon can be a limiting factor. The processes have also been used to deposit superlattices of TiC/NbC and TiC/VC at 400-500°C as well as epitaxial ternary Tix V1-xCy films. Furthermore, epitaxial films of ternary carbides with well-controlled metal concentration profiles can be deposited at temperatures below 500°C. © 2001 Elsevier Science B.V. All rights reserved.
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| 12. |
- Jensen, J.A.D., et al.
(author)
-
Electrochemically deposited nickel membranes, process-microstructure-property relationships
- 2003
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 172:1, s. 79-89
-
Journal article (peer-reviewed)abstract
- This paper reports on the manufacturing, surface morphology, internal structure and mechanical properties of Ni-foils used as membranes in reference-microphones. Two types of foils, referred to as S-type and 0-type foils, were electrochemically deposited from a Watts-type electrolyte, with (S-type) or without (0-type) the use of the sulfur-containing additive sodium saccharin. Both types of Ni-foils appeared perfectly smooth when investigated with scanning electron microscopy (SEM), while atomic force microscopy (AFM) and transmission electron microscopy (TEM) revealed differences in the surface morphologies and a smaller grain-size in the S-type foils. X-Ray diffraction showed a <311> texture component in both types of Ni-foils, most pronounced for 0-type foils. A minor <111> texture component observed in both foil types was strongest in the S-type foils. Mechanically 0-type foils proved more ductile than S-type foils during thin film tensile testing, due to microstructural defects caused by sodium saccharin during deposition. Tensile strengths in the order of 700-1000 MPa were observed - highest for the more ductile 0-type foils. A hardness in the order of 6 GPa (590 HV) was found by nanoindentation. © 2003 Elsevier Science B.V. All rights reserved.
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| 13. |
- Jinnestrand, Magnus, et al.
(author)
-
Investigation by 3D FE simulations of delamination crack initiation in TBC caused by alumina growth
- 2001
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 135:2-3, s. 188-195
-
Journal article (peer-reviewed)abstract
- In gas turbines, thermal barrier coatings (TBCs) applied by air plasma spraying are widely used to reduce the temperature in hot components. The TBC allows higher gas temperature and/or reduces the need for internal cooling in the hot components, thus increasing the efficiency of the gas turbine. Spallation is a common failure mechanism of TBC and occurs after a critical number of thermal cycles, when the alumina layer has grown to a critical thickness. The influence of the growing alumina layer and the top/bond-coat interface roughness in the TBC has been investigated. The primary goal was to identify failure mechanisms that can be incorporated into a life model of the TBC, and to increase the understanding of the delamination process in the TBC. A new formulation of alumina growth is proposed, in which the swelling strains caused by the volumetric increase during alumina growth depends on the stress state. The alumina growth model is used in 3D FE thermal cycling simulations of a TBC in which the thermal cycle time is long enough to characterize a typical cycle of a gas turbine. From the simulations, the growing alumina layer is observed to be one failure mechanism of the TBC. Without an alumina layer in the model, high delamination stress is observed at room temperature, above ridges of the top/bond-coat interface in the top coat. When the alumina is growing, the point of maximum delamination stress is moved towards the valleys. When the thickness of the alumina layer has grown to approximately 8–10 μm, positive delamination stress is found above the valleys in the top coat. The movement of the positive delamination stress region can explain why a delamination crack develops, which will cause spallation of the TBC during shutdown to room temperature.
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| 14. |
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| 15. |
- Kish, L.B., et al.
(author)
-
In situ electrical transport measurements and self-organization in gold nanoparticle films during and after deposition
- 2001
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 142-144, s. 1088-1093
-
Journal article (peer-reviewed)abstract
- In the first part of this paper, a new method is shown which is able to predict the particle size of conductive nanoparticle films in situ, during deposition. The method is used for the measurement of the time-derivative of conductance fluctuations during deposition. The second part of the paper deals with in situ conductance measurements on gold films during deposition. During the measurement, various electrical fields have been applied in order to study the possible influence of the field magnitude on the film formation. The observed effects have been interpreted by the biased percolation model. A possible technological application of the observed phenomenon is the fabrication of nanoparticle films with controlled disorder, e.g. in chemical sensors. © 2001 Elsevier Science B.V. All rights reserved.
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| 16. |
- Nakao, S., et al.
(author)
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Influence of high-energy Si+ ion irradiation on microstructure and mechanical properties of alumina films
- 2002
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 158-159, s. 534-537
-
Journal article (peer-reviewed)abstract
- Amorphous alumina films, approximately 600 nm in thickness, prepared on Si(100) substrates by RF magnetron sputtering were irradiated with 2.0 MeV Si ions at a dose of 1 × 1017 ions/cm2 and the influence on the composition, microstructure, and mechanical properties was examined by Rutherford backscattering. X-ray diffraction and nano-indentation measurements. It was found that the O/Al ratio in the films was approximately 1.5, and there was no significant alteration in this ratio after ion irradiation. However, a structural change from amorphous to the crystalline ?-alumina was observed. Hardness and elastic modulus of the irradiated film were significantly increased from approximately 11 and 181 GPa up to approximately 25 and 246 GPa, respectively. © 2002 Elsevier Science B.V. All rights reserved.
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| 17. |
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| 18. |
- Rubel, M., et al.
(author)
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Behavior of SiC-Al coatings upon high dose irradiation with deuterium and helium ions
- 1994
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In: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 64:3, s. 205-211
-
Journal article (peer-reviewed)abstract
- Al-SiC coatings obtained by vacuum plasma spraying co-deposition are considered as a new class of plasma-facing materials (PFMs) for fusion devices. The technical requirements for PFMs are stringent, since they have to withstand severe operation conditions, including bombardment by high fluxes of particles escaping the plasma. A number of Al-SiC coatings (containing 20 or 50wt.% SiC) deposited on Cu, stainless steel or graphite substrates were irradiated under laboratory conditions with high doses of deuterium or He ions. The surface properties of the materials were characterized before and after irradiation using several analytical techniques (Rutherford backscattering, nuclear reaction analysis, secondary ion mass spectrometry, Auger electron spectroscopy, energy-dispersive spectroscopy, microscopic methods and laser profilometry). Exposure to low-energy deuterium ions or deuterium plasma resulted in the implantation of 7-9 × 1016 D cm-2 in the near-surface layer. The initial steps of blister formation were also observed. Changes in the surface structure were noted following irradiation with 5He+ ions (1.7-2 MeV). Damage in the surface layer of the materials was dependent on the ion flux.
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| 19. |
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| 20. |
- Wänstrand, Olle, et al.
(author)
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An experimental method for evaluation of the load carrying capacity of coated aluminium : the influence of coating stiffness, hardness and thickness
- 2000
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 127:2-3, s. 107-113
-
Journal article (peer-reviewed)abstract
- If a brittle ceramic PVD coating is applied to a soft and compliant material such as aluminium, it might crack when the component is taken into use, i.e. when it is loaded. This means that the load-carryingcapacity of the soft Al substrate has to be improved if a PVD coating should be applied successfully. One solution is to introduce a relatively thick intermediate load-carrying layer between the soft substrate and the thin ceramic PVD coating. This paper presents a new experimental test method to find the load-carrying layer thickness required to protect a soft substrate from plastic deformation. The method is evaluated, but also used to investigate different load-carrying layers on aluminium. In the experiment, rigid cemented carbide balls were used to indent aluminiumcoated with, compared with PVD coatings, relatively thick (50–150 μm) foils. The foils were firmly attached to the aluminium substrates using a fusible and strong adhesive. After indentation the foil/coating was detached and the amount of plastic deformation on the substrate surface was determined by measuring the depth of the residual indent. The influence of foil thickness, stiffness and hardness on the resistance to plastic substrate deformation was studied. It was found that the technique of gluing foils on Al well simulates the load-carrying properties of a traditionally deposited layer. The indentation experiments also showed that the load-carryingcapacity of the coatedaluminium increases with the thickness of the foil and the elastic modulus of the foil. No significant influence of the foil/coating hardness on the load-carryingcapacity could be seen.
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| 21. |
- Yamamoto, K., et al.
(author)
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Structural features of thick c-boron nitride coatings deposited via a graded B-C-N interlayer
- 2001
-
In: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 142-144, s. 881-888
-
Journal article (peer-reviewed)abstract
- Thick c-BN films (up to 2.7 µm) were deposited onto Si substrates by an r.f. diode apparatus using boron carbide (B4C) targets. The c-BN films were deposited on a compositionally graded interlayer, which consisted of B, C and N. A thin B4C layer (~200 nm) had been initially deposited onto Si substrate in a pure Ar gas discharge. The following formation of the graded interlayer was conducted by the step-like or smoothly replacing Ar with N2 gas. Depending on the method implemented, the secondary ion mass spectroscopy (SIMS) depth profile showed relatively smooth or step-like changes in the elemental concentration of B, C and N. The primary analysis on the chemical bond of the graded interlayer was conducted by measuring the chemical shift of B1s, C1s and N1s spectra by X-ray photoelectron spectrometry (XPS). It is shown that the B-C bond, which was a major bonding component in the B4C layer, was gradually replaced by a mixture of B-N and C-C bond as the N2 fraction was increased. Transmission electron microscopy (TEM) images of the gradient layer showed that (0002) oriented turbostratic BN (t-BN) structure started to appear after the N2 concentration was increased by more than 2%. It was also observed that the c-BN phase nucleated non-uniformly in the gradient layer at 10% of N2 fraction. © 2001 Elsevier Science B.V. All rights reserved.
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| 22. |
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| 23. |
- Abadias, Gregory, et al.
(author)
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Preface
- 2020
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In: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 404
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Journal article (other academic/artistic)abstract
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| 24. |
- Abou Nada, Fahd Jouda, et al.
(author)
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Remote temperature sensing on and beneath atmospheric plasma sprayed thermal barrier coatings using thermographic phosphors
- 2016
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In: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 302, s. 359-367
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Journal article (peer-reviewed)abstract
- Investigations on remote temperature sensing of yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) at the surface and at the bond-coat/top-coat interface were carried out. Using Y2O3:Eu thermographic phosphor as an embedded temperature sensing layer, sub-surface temperature probing through 300 μm of atmospheric plasma sprayed YSZ is demonstrated. The Y2O3:Eu thermographic phosphor displays a temperature sensitivity ranging between 400 °C up to a maximum of 900 °C when utilizing the luminescence originating from the 611 nm emission band. Dysprosium stabilized zirconia (10 wt.% DySZ), a TBC material, is also investigated and established as a temperature sensor from 400 °C up to a temperature of 1000 °C using both the intensity decay time and emission intensity ratio methods. In addition, the luminescence of presumed optically inactive YSZ materials was spectroscopically investigated in terms of optical interferences caused by impurities. A validation temperature probing measurement through 300 μm of YSZ top-coat was successfully performed in a SGT-800 Siemens burner running at six different operating conditions in an atmospheric combustion rig.
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| 25. |
- Aghasibeig, Maniya, et al.
(author)
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Laser cladding of a featureless iron-based alloy
- 2012
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In: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 209, s. 32-37
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Journal article (peer-reviewed)abstract
- Laser cladding experiments with powder injection technique were carried out to create coatings of Fe-8.1Cr6.4Mn-5.3Si-6.9Mo-3.6C alloy on AISI 1018 steel substrates using a diode laser. Analysis of the clad layers showed that an almost featureless structure was formed at different dilutions between 1% and 4%. The featureless phase with a high hardness of 1155 HV was characterized as a metastable solid solution of e phase. However, the featureless structure appeared to be very brittle with numerous cracks. After heat-treatment, it decomposed into a bainitic structure with a high hardness of 884 HV.
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