Surface and Coatings Technology (SURF COAT TECH )

Publisher: Elsevier

Description

The increasing requirement for high technology materials with specific performance characteristics in various types of environments has dictated that these materials possess near-surface properties different from their bulk properties. Surface and Coatings Technology is a principal forum for the interchange of information on the science, technology and applications of thin and thick coatings and modified surfaces which alter the properties of materials. The scope includes all types of coatings and surface modification techniques (including physical vapour deposition, chemical vapour deposition, electroplating and surface modification by directed energy techniques). Of particular emphasis are the emerging advanced processes such as thermal spraying, sputter deposition, activated reactive evaporation, ion plating, molecular beam epitaxy, ion implantation and pulsed laser surface deposition. Contributions range from original scientific articles concerned with applied research or direct applications of coatings to reviews of current technology in specific areas. Articles are solicited on topics which include one or more of the following areas: (1) characterization of coatings and modified surfaces, which includes the determination of composition, structure, adhesion, and internal stresses; (2) the application of coatings and modified surfaces to alter the mechanical, chemical or optical properties of materials. Mechanical properties include friction, wear, erosion, hardness and load bearing capacity. Chemical properties include corrosion and oxidation. Optical and electro-optical properties include reflectivity, selective absorption and electroluminescence. Particular emphasis is also placed on the emerging surface engineering technologies and coatings with a diversity of applications such as diamond, diamond-like carbon, and cubic borin nitride. Other interdisciplinary areas include thermal barrier coatings and coatings for biomedical applications, materials conservation, and environmental applications. Technical Notes are also solicited for the Current Industrial Practices section which is intended for more engineering-oriented articles which should include, for example, developments of coatings deposition equipment (including production systems) and cost/benefit analysis for specific types of coatings.

Impact factor 2.20

  • Hide impact factor history
     
    Impact factor
  • 5-year impact
    2.10
  • Cited half-life
    7.00
  • Immediacy index
    0.30
  • Eigenfactor
    0.04
  • Article influence
    0.57
  • Website
    Surface and Coatings Technology website
  • Other titles
    Surface & coatings technology (Online), Surface and coatings technology
  • ISSN
    1879-3347
  • OCLC
    39265083
  • Material type
    Document, Periodical, Internet resource
  • Document type
    Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Elsevier

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • Pre-print allowed on any website or open access repository
    • Voluntary deposit by author of authors post-print allowed on authors' personal website, arXiv.org or institutions open scholarly website including Institutional Repository, without embargo, where there is not a policy or mandate
    • Deposit due to Funding Body, Institutional and Governmental policy or mandate only allowed where separate agreement between repository and the publisher exists.
    • Permitted deposit due to Funding Body, Institutional and Governmental policy or mandate, may be required to comply with embargo periods of 12 months to 48 months .
    • Set statement to accompany deposit
    • Published source must be acknowledged
    • Must link to journal home page or articles' DOI
    • Publisher's version/PDF cannot be used
    • Articles in some journals can be made Open Access on payment of additional charge
    • NIH Authors articles will be submitted to PubMed Central after 12 months
    • Publisher last contacted on 18/10/2013
  • Classification
    ​ green

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: To provide semi-permanent antibacterial function for titanium medical implements, such as micro-tweezers, hemostatic forceps, and needle holders, a visible-light responsive nitrogen-doped titanium dioxide (TiO2) layer that strongly adheres to Ti materials was fabricated through anodization in an electrolyte comprising ammonium nitrate in ethylene glycol, followed by heating at 723 K in air. The predominant structure of the oxide layer was TiO2 with a rutile structure that contained ca. 1 at.% of incorporated nitrogen. The outward appearance of the oxide layer was quite smooth, and the topographic microstructure was a flat surface that included small pores. The thickness of the surface layer was approximately 10 μm, and the layer strongly adhered to Ti substrates. This fabricated anodic layer acted as a photocatalyst both under UV-light and visible-light illumination, and showed excellent antibacterial performance under both types of illumination. Anodic oxidation in a nitrate/ethylene glycol electrolyte is an innovative surface modification technique that can be used to simply form visible-light responsive photocatalytic antibacterial coatings on biomedical Ti materials.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: Carbon implantation is used to change the surface properties of materials without changing the bulk properties in various fields such as microelectronics, optics, tribology and biomaterials. While this implantation is usually performed at energies lower than 200 keV and thus in the low energy range of the stopping power curve, here we studied the effect of a 1 MeV ion beam which is in the medium energy range. The higher energies increase the modified depth range and thereby the load-carrying ability of metal surfaces. Light (Al), medium (Co) and heavy (W) metals were chosen as substrates. Three ion fluencies of 1016 ions/cm2, 1017 ions/cm2, and 1018 ions/cm2 were used. Nuclear reaction analysis evidenced the presence of carbon at the samples surface and at a depth in accordance with Monte-Carlo (SRIM) simulations. Glancing incidence X-ray diffraction (GIXRD) allowed us to reveal the formation of aluminum carbide while no carbide was observed for Co and W. The modifications of the lattice parameters of Co and of W were studied by Rietveld refinements of X-ray diffraction patterns. For these metals the increase of the profile asymmetry of the diffraction peaks can result from the generation of dislocations induced by irradiation. The hardness measured by nano-indentation tests increases with the carbon ion dose, and the rise of hardness is larger for aluminum and tungsten than for cobalt.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: HAp and HAp/ZrO2 composite coatings were successfully electrodepesited on 316L stainless steel substrates in the solutions containing ZrO2 particles at different concentrations. The effects of ZrO2 content on characteristics of the coatings were investigated using X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM) and bonding strength test. Polarization and electrochemical impedance spectroscopy measurements were carried out in order to evaluate corrosion behavior of the coatings. In-vitro test in SBF and further SEM observations were performed to examine bioactivity of the coatings. HAp/ZrO2 composite coatings showed better electrochemical behavior and higher bonding strength than pure HAp owing to higher crystallinity and less porosity in microstructure. Additionally, it was found that the function of ZrO2 is highly dependent on the content and uniformity of ZrO2 dispersion in microstructure. The least corrosion rate and bonding strength were obtained at ZrO2 concentration of 10 g/L, in which corrosion resistance of the composite coating was improved 30 times and bonding strength between the coating and the substrate increased from 11.6 MPa in pure HAp to 20.8 MPa in composite coatings.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: The recent developments in the field of hot dip zinc coating are reviewed with special reference to different industrial applications. The improvements in physical and chemical structural composition due to pre- and post-modification processes are discussed. The present review has the focus mainly on the readership of young researchers engaged in this field. Very recent developments on the hot dip galvanization processes are highlighted. Their industrial competencies with aluminium dipping are also briefly discussed. The scopes for immediate future developments are also highlighted then and there.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: FeCoCrAlCu high-entropy alloy coating was synthesized on Q235 steel with premixed high-purity Co, Cr, Al and Cu four-component powders on a Fe-base alloy by laser surface alloying. Constituent phases, microstructure and chemical composition of the coating were investigated using XRD, SEM, and EDS, respectively. Surface mechanical property and wear resistance were also studied. Results showed that the FeCoCrAlCu coating was ~ 800 μm in thickness, and a hard high-entropy alloy coating with good metallurgical bonding to the substrate was obtained. FeCoCrAlCu coating was composed of a single BCC solid solution. The microstructure of the coating exhibited a typical dendrite structure growing from the substrate. The microhardness of the FeCoCrAlCu coating was ~ 3 times that of the Fe-base alloy substrate. The wear resistance of the FeCoCrAlCu coating was also improved. Both the wear volume and specific wear rate of the coating are an order of magnitude lower than that of the Q235 substrate under a dry sliding condition, which might be attributed to the fact that the wear resistance is proportional to the alloy hardness according to Archard's law.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: Gadolinium oxide (Gd2O3) thin films were deposited on Si (100) and quartz substrates at different substrate temperatures (300–873 K) and oxygen partial pressures (0.002–2 Pa) by pulsed laser deposition technique. The microstructure of the films was analyzed by X-ray diffraction (XRD), atomic force microscopy and Raman spectroscopy. The XRD pattern shows the presence of monoclinic phase of Gd2O3 as a major phase along with a small volume fraction of cubic phase at lower substrate temperatures. Optical transmittance and absorbance of the Gd2O3 films were measured by UV–visible spectrophotometer. The films deposited at different deposition conditions show a strong absorbance at ~ 220 nm and exhibit transmittance in the range of 70–90%. Highest value of band gap (~ 5.80 eV) is obtained for the Gd2O3 film deposited at 873 K.
    Surface and Coatings Technology 01/2015; 262.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, two types of blended alloys were processed by plasma transferred arc (PTA) hardfacing to form coatings. In the first case, a pre-alloyed Cu-Sn alloy and a pre-alloyed Co-base alloy were blended at a weight ratio of 85:15 (Cu-Sn/Co-base). In the second case, the pre-alloyed Cu-Sn and Co-base alloys were mixed with the molybdenum (Mo) element at a weight ratio of 81:15:4 (Cu-Sn/Co-base/Mo). Metastable liquid phase separation formed in the Cu-Sn/Co-base and Cu-Sn/Co-base/Mo coatings. The Co-rich spheroids as the minor precipitating alloy particles distributed on the Cu-rich matrix. The Co-rich spheroids consisted of α(Co) and M7C3 phases, and the Cu-rich matrix included α(Cu, Sn) and Cu10Sn3 phases. The relative content of α(Co) + M7C3 phases in the Cu-Sn/Co-base/Mo coating was higher than that in the Cu-Sn/Co-base coating. The numbers of the Co-rich spheroids in the cross section of the Cu-Sn/Co-base coating increased with increasing the distance from the substrate, and an obvious macroscopic segregation could be found in the coating close to its substrate. When Mo as additive was further added, the numbers of the Co-rich spheroids in the cross section of the coating increased and the macroscopic segregation could not be seen when compared to that in the Cu-Sn/Co-base coating. The wear rate of the Cu-Sn/Co-base and Cu-Sn/Co-base/Mo coatings was lower than that of the Cu-Sn coating, and a distinct improvement of the wear rate could be obtained in the Cu-Su/Co-base/Mo coating, attributing to mainly the increasing hardness of the coatings by sequence of the Cu-Sn coating, Cu-Sn/Co-base coating, and Cu-Sn/Co-base/Mo coating. The friction coefficient of the coatings has an increasing trend by sequence of the Cu-Sn coating, Cu-Sn/Co-base coating, and Cu-Sn/Co-base/Mo coating, but an obvious difference could not be seen in the coatings.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: Fluorine-free superhydrophobic cotton fabrics with photocatalytic self-cleaning property were prepared by the combination of photoactive TiO2 and superhydrophobic SiO2. Organically modified silica (ormosil) aerogel with a high surface area and high porosity was first prepared. TiO2 nanocrystals were then synthesized and simultaneously deposited onto preformed porous ormosil aerogel at low temperature (below 100 °C) to obtain TiO2–SiO2 composite particles. XRD measurements prove that the formed TiO2 is of anatase phase. SEM and TEM images disclose the highly porous structure of the TiO2–SiO2 composite particles and further confirm the existence of highly crystalline TiO2 within the SiO2 matrix. IR spectra indicate the presence of abundant methyl groups on the TiO2–SiO2 composite particle surface. BET measurements show a high surface area of 379.0 m2/g for the TiO2–SiO2 composite particles, which is advantageous to enhance the photocatalysis. The cotton fabrics coated with TiO2–SiO2 composite particles exhibit superhydrophobicity with a water contact angle of 160.5°. However, the superhydrophobic cotton fabrics can be easily wetted by oil dirt and become superhydrophilic. Herein, the TiO2–SiO2 composite particle coated cotton fabric, which was contaminated with oleic acid, can recover its superhydrophobicity after UV irradiation for 4 h.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: Nanostructured Al2O3–ZrO2/SiO2 multilayer coating was applied on 316L SS specimens using dip-coating method. Then, the coated specimens on heat treatment to 800, 900, and 1000 °C for 100 h showed the formation of a stable structural phase of t-ZrO2-toughened Al2SiO5 along with ZrSiO4. The microstructural images of the heat-treated specimens observed the level of porosity and that of BHJ-pore size distribution was decreased in the coating along with crack splats. Then, the coating was subjected to cyclic oxidation and hot corrosion test for 20 cycles. The obtained results showed that the rate of cyclic oxidation resistance enhanced when compared to that of hot corrosion resistance. The results of X-ray diffraction analysis showed hot corrosion resistance in molten salt, with non-leaching t-ZrO2 structural phase of ceramic coating. The mechanical properties of the nanostructured coating improved with an increase in the heat treatment. The maximum hardness (H) and reduced elastic modulus (Er) values of the coating were approximately 18.43 ± 0.62 and 68.30 ± 1.35 GPa, respectively. Spallation and oxidation resistance of the coating were explored through mechanical properties, in situ scanning probe microscopy, and atomic force microscopy. The results showed that silicate-based thermal barrier coating provided better protection to SS specimen from high-temperature corrosion.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: The objective of the present work is to understand the microstructural evolution in Cu–Sn coatings with varying Sn content (3–6.5 wt.%) deposited on steel substrate via immersion coating method and its effect on interfacial adhesion with styrene butadiene (SBR) based bead rubber. The phase formation prediction in different Cu–Sn alloy systems from Pourbaix diagrams constructed using FactSage revealed the formation of higher amount of SnO2 with an increase in Sn content in the coatings. Quantitative depth profiling by glow discharge optical emission spectroscopy, microstructural characterization by transmission electron microscopy and phase analysis by grazing incidence X-ray diffraction confirmed the presence of Cu3Sn precipitates with increasing volume fraction as Sn content in coatings increases. Adhesion strength measured by performing pull-out test on the SBR rubber vulcanized Cu–Sn coated steel wire samples exhibited maximum value for Cu–5 wt.% Sn coating. The formation of Cu3Sn and SnO2 played crucial role in controlling the Cu activity at the coating–rubber interface to form optimally thick Cu-sulfide layer in Cu–5 wt.% Sn coating and thus provided the maximum adhesion strength.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: In this paper, an improved three-dimensional (3D) numerical model for erosion process was developed in which multiple solid particles were adopted for characterizing the accumulation of damage. In this model, the metal-ceramic composite materials were coated on nickel-base superalloy. The explicit solver LS-DYNA has been used to simulate the erosion process. The effects of the coating thickness, particle size and impingement velocity on the stress distribution and damage of the target material were studied. The simulation results show that the reasonable coating thickness can effectively prevent its peeling. With the increase of impact velocity, radial and lateral cracks are initiating and propagating on the coating surface. Particle size has the significant influence on the coating loss. This multiple particle model can help understanding and predicting the erosion results better than conventional FE simulations.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: Nano NiO particles, prepared by wet chemical precipitation method using nickel nitrate as precursor, were characterized using different techniques including XRD, UV spectroscopy, HRTEM, FTIR spectroscopy and Micro Raman spectroscopy. The effects of nano NiO incorporation on enhancement of electrocatalytic efficiency of the electroless Ni–P coatings for hydrogen evolution reactions (HERs) in alkaline medium were systematically investigated in this paper with respect to both metallurgical and electrochemical characteristics. An improvement in the hardness and thickness of electroless coatings along with a mirostructural surface grain refinement was achieved by the incorporation of the nano NiO into the Ni–P matrix. The long term stability of nano NiO incorporated coatings in alkaline medium was ensured by open circuit potential (OCP) analysis. The composite incorporated coatings exhibited a substantial reduction in overpotential during HER studies in 32% NaOH medium. The role of nano NiO on enhancement of electrocatalytic efficiency of the coatings for catalytic HER is evident from the results of potentiodynamic polarization and cyclic voltammetric studies.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: Intumescent flame retardant coating, composed of cationic chitosan and anion ammonium polyphosphate, has been constructed on cotton fabric by layer-by-layer assembly technique. The result of Fourier transform infrared spectroscopy confirmed that the assembly coating was successfully deposited on fabric and the coating quantity increased linearly with the growth of bilayer number. Evaluation of thermal and flammability properties showed increased residual chars at 700 °C in air during thermogravimetric analysis and decreased peak heat release rates and total heat releases in microscale combustibility test for the coated fabrics, as compared with the uncoated. Significantly, in vertical flame test the residues of the coated fabrics perfectly remained the textile structure and fiber shape with respectable strength, indicating that the intumescent coating show an excellent flame retardant efficiency on cotton. These results demonstrated a completely intumescent coating for cotton via layer-by-layer assembly technique which provides an effective alternative to phosphorus-based coating.
    Surface and Coatings Technology 01/2015; 262.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The electrocodeposition of Ni-TiO2 nanocomposite single layers and Ni-TiO2/TiO2 multilayers from a Watts bath containing a TiO2 sol on copper substrates was investigated by different deposition techniques. Compared with direct current (DC) deposition, both pulse plating (PP) and pulse reverse plating (PRP) facilitated higher incorporations of TiO2 nanoparticles. Morphological studies conducted by scanning electron microscopy and field emission scanning electron microscopy revealed that the microstructure of the Ni-TiO2 nanocomposite coatings are affected both by pulse potentials and durations, indicating that higher incorporations of TiO2 nanoparticles refine the microstructure. The results of the morphological studies also confirmed the formation of a multilayer structure consisting of Ni-TiO2 and TiO2-rich layers by limiting the nickel deposition through a diffusion control mechanism. The structures of the nanocomposite coatings were characterized by X-ray diffraction (XRD). The preferred orientations and crystallite sizes of the Ni matrices with face-centered cubic structures were influenced by the PP and PRP parameters. Furthermore, the XRD results confirmed the presence of an anatase phase in the nanocomposite coatings after 3 h of heat treatment at 450 °C and the formation of crystalline NiO was developed by PRP. The corrosion behaviors of the coatings in 1 M NaCl and 0.5 M H2SO4 electrolytes were compared by means of potentiodynamic polarization and electrochemical impedance spectroscopy techniques. Increases in corrosion resistance and passivation tendency were favored by TiO2 incorporation, and the multilayers exhibited the highest corrosion resistance compared to all of the Ni-TiO2 nanocomposite single layers and the pure Ni coating.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: The surface of low-density ceramic (LDC) material was modified by using high-viscosity silica sol. The optimal preparation parameters for the sol were obtained using an orthogonal experimental design. The influence of the drying condition on the coating quality and even on the value of fine particulate matter after filtering (VFPM2.5) was studied. The coating morphology was characterized by using scanning electron microscope (SEM). The results indicate that the VFPM2.5 decreased from 25.2 μg/m3 to 0.3 μg/m3. The regeneration performance of the LDC filter elements was significantly improved by the surface modification. The baseline pressure drop using the LDC with the coating is less than 138.61 Pa. The results show that the coating makes a negligible effect on the pressure drop in comparison with the conventional method of modification. Moreover, the LDC with the coating demonstrated great isothermal oxidation performance and thermal shock resistance during the filtration process.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: This paper presents the out-of-phase thermo-mechanical stress analysis of thermal barrier coating (TBC) system in real working conditions used as thermal barrier in diesel engine cylinder heads. The coating system in this research comprises 350 μm zirconium oxide top coat (TC) and 150 μm metallic bond coat (BC). These layers were deposited on the substrate, aluminum A356 alloy, by the aid of air plasma spray (APS) method. Afterwards, the specimen was subjected to thermo-mechanical fatigue (TMF) loadings. Based on the experimental conditions, FE simulations were performed by both time-independent and time-dependent substrate material properties in ABAQUS software. Simulation results related to heat transfer analysis demonstrate only about 10.5% comparative error compared to experimental results. Moreover, defining time-dependent properties, which were obtained from two-layer visco-plastic model, yields results with 15% less comparative error in comparison to the results based on time-independent material properties. In addition, the effects of roughness and porosity in coating layers and substrate were studied on three different models by the aid of a scanning electron microscopy image. Obtained results based on real geometry illustrate that consideration of porosity in TC layer has an effective role in the stress distribution of this layer. However, BC layer stress distribution is much more dependent on interface morphology.
    Surface and Coatings Technology 01/2015; 262.
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    ABSTRACT: Nanostructured diamond (NSD) films were deposited by chemical vapor deposition (CVD) on both 440C stainless steel ball bearings and 316 stainless steel discs through the use of a metal-boride interlayer. The interlayer is deposited by means of a novel method using microwave plasma CVD with a feedgas mixture composed of hydrogen (H2) and diborane (B2H6). Substrate temperature was found to have a profound effect on the boride interlayer composition and stoichiometry, forming either a predominantly CrB or Fe2B interlayer. Fe2B-based interlayers were found to be effective in blocking the mutual diffusion of carbon and iron that would otherwise produce graphitic carbon and lead to poor NSD adhesion. Fully continuous and adhered nanostructured NSD films are grown using this interlayer, particularly on 316 steel discs.
    Surface and Coatings Technology 01/2015; 261.
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    ABSTRACT: Tools and dies used in hot metal forming are exposed to very demanding contact conditions, including elevated temperatures, high contact pressures and abrasive flow of work material, which lead to different types of tool damage. However, the most critical ones are wear and fatigue fracture. As the focus shifts toward the use of new lightweight high-strength materials, also requirements on tool properties are becoming more demanding. This requires use of surface engineering techniques like nitriding and PACVD coating and proper balance between hardness and fracture toughness. Vacuum heat treatment allows the optimization of the tool steel microstructure, which may result in increased fracture toughness while maintaining or even increasing hardness, which enhances possibilities of using coated forming tools.
    Surface and Coatings Technology 01/2015; 261.
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    ABSTRACT: The effect of deposition temperature on deposition kinetics and mechanism of silicon boron nitride (SiBN) coating was investigated from SiCl4–BCl3–NH3–H2–Ar mixture using low pressure chemical vapor deposition (LPCVD). Results showed that the deposition rates increased from 700 °C to 1030 °C, and then decreased above 1030 °C. The relative content of silicon increased with increasing deposition temperature. The SiBN coating was of amorphous phase and its surface morphology showed cauliflower-like. The bonding states of SiBN coating were the B–N and Si–N bonding at all deposition temperatures, which demonstrated that the SiBN coating is composed of very small Si–N and B–N particles and the main deposition mechanisms refer to two parallel reaction systems of BCl3 + NH3 and SiCl4 + NH3. The deposition reactions were mainly controlled by BCl3 + NH3 under 900 °C, and by SiCl4 + NH3 over 900 °C.
    Surface and Coatings Technology 01/2015; 261.
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    ABSTRACT: This paper presents the results of research on the deposition of gradient antiwear Ti/TiC/a-C:H coatings on Al–Zn alloys (7075 series) using a hybrid method Radio Frequency Plasma Assisted Chemical Vapor Deposition (RF PACVD). In order to eliminate the over-aging effect of the aluminum substrate it was subjected to T6I6 treatment. The alloy has been strengthened by precipitation and a first aging process, at a temperature of 813 K for 6 h and at 430 K for 1 h, respectively. Synthesis of the gradient coatings on 7075 aluminum alloy was performed simultaneously during the second stage of the aging process at 390 K for 6.5 h. It has been proved that the change in the substrate bias potential in the range of 150–600 V (constant value for each process) influences the mechanical properties of the resulting coatings (hardness in the range 10–19 GPa and adhesion to the substrate from 16 up to 33 mN). It has been proved in this case that during the substrate aging process it is possible to control the contribution of disordered carbon. Its value (calculated as D/G area ratio) in the range of 0.75 allows obtaining coatings with a coefficient of friction of about 0.05 (Al2O3 or Si3N4 counterparts, 5 N load) and wear rates of about 4.4 ∗ 10− 5 mm3/Nm, which due to their chemical structure behaves as solid lubricant in the friction pair.
    Surface and Coatings Technology 01/2015; 261:304–310.