PVD Method Research Articles

Industrial Preparation of SiC Ceramic Coating for High Temperature and Anti-Oxidation of C/C Composites

A SiC ceramic coating for high temperature and anti-oxidation was prepared by high temperature reaction and PVD methods inside industrial synthetic furnace of SiC. Its phase composition and microstructure were characterized by using XRD, SEM,and its high temperature anti-oxidation property were studied by isothermal oxidation tests.The results showed that the coating is composed of mainly α-SiC and β-SiC,the coating is uniform, compact, perfect grain growth, without crack, closely with the C/C materials,the thickness is about 600μm. After 10h oxidation in air at 1773 k the weight loss of the coating was only 0.3%,which implies that the coating has excellent anti-oxidation ability.

J161013 CNTsと金ナノ粒子を用いた局在表面プラズモン共鳴センサの感度向上([J16101]マイクロナノメカト口ニクス(1))

In the conventional sensor using localized surface Plasmon resonance, the metallic particle has only allocated on substrate in two dimensions. We attempted that Gold nanoparticles allocated on the substrate in three dimensions were fabricated by growing CNTs on the Si substrate by the CVD method, and modifying gold nanoparticles by the PVD method. Concretely, we fabricated High density and low density CNTs on the substrate by the CVD method, and modified gold nanoparticles to each CNTs by thermal deposition and vacuum deposition. Evaluation of applicability to bio-sensor was carried out by using protein absorption. BSA of 0.1g/1 as a protein was applied to the absorption test. Absorption spectra of before and after were compared by the LSPR analysis. After BSA adhesion, a spectrum shift to the infrared region was seen in low density CNTs that gold nanoparticle was modified by thermal deposition.

Anti-wear multilayer coatings based on chromium nitride for wood machining tools

The performed experiments revealed that the anti-wear resistance of chromium nitride and chromium carbonitride multilayer coatings obtained by the PVD method was higher than each of the phases separately. The CrN/CrCN coatings were obtained using cathodic arc evaporation. They consisted of seven modules, each approximately 400 nm thick, characterised by different thickness ratio of the CrN and CrCN layers in the modulus. A layer of chromium 0.1 μm thick was used as a sublayer. The adhesion of the coatings was determined using scratch test and Rockwell test. Hardness and stress as well as friction and wear coefficients when used to work timber were determined. Industrial milling tests of dry wood were carried out. The results of above measurements showed that the best useful properties were observed when the thickness ratio in coatings’ module was 2:1 which could be attributed to its very good adhesion to the substrate (about 115 N) and low wear rate. The tools with multilayer CrN/CrCN coatings improve the quality of the treated wood surface in comparison with uncoated knives.

Film thickness dependence on the optical properties of sputtered and UHV deposited Ti thin films

Titanium films of different thicknesses were deposited on glass substrates, using planar magnetron sputtering at 313 K substrate temperature. Their optical properties were measured by spectrophotometry in the spectral range of 200–2500 nm. Kramers–Kronig method was used for the analysis of the reflectivity curves of Ti films to obtain the optical constants of the films. In order to compare the influence of thickness of Ti films prepared using two different PVD methods, namely sputtering and electron gun depositions on the optical properties of Ti films, the optical results of Savaloni and Kangarloo (2007) for Ti films produced using electron gun deposition under UHV condition at 313 K substrate temperature are incorporated in this work. The analysis of the residual stress in the sputter deposited films using sin 2 ψ technique and the nano-strain in the E. Gun deposited films obtained from X-ray diffraction line broadening analysis (Warren–Averbach method) showed consistency with the results obtained for optical functions and agreed well with the predictions of both structural zone model (SZM) and effective medium approximation (EMA) results. Therefore, a direct correlation between the optical properties and the processes involved in the evolution of thin films is established. The optical data, in particular the conductivity results for sputter deposited Ti films show more agreement with those of bulk sample (Lynch et al., 1975), while those of UHV E. Gun deposited films are more consistent with those of thin film sample (Johnson and Christy, 1974).

Optimization of a container design for depositing uniform metal coatings on glass microspheres by magnetron sputtering

Coating granular substrates by PVD methods like magnetron sputtering is a very challenging process. Although many of such substrates may also be coated by other means like the sol gel method, there are coating materials (e. g. refractory metals) for which PVD processes are the method of choice.One of these substrates is hollow glass microspheres with 2–80μm diameter which can be used for hydrogen storage if a proper catalytic film is applied. To achieve a uniform film by magnetron sputtering on all the spheres a special apparatus was used which basically consists of rotating vessels positioned beneath the target. The arising problems of agglutination of the powdery substrate were solved by designing a special coating vessel, where the spheres are contained during deposition.For testing the system first copper was used as a target material, which was then replaced by platinum since the glass microspheres are used for a catalytic application. The film thickness on the spheres was determined by optical absorption and matches well with the thickness calculated for the special vessel geometry. Additionally it is shown that the glass microspheres can be coated with a uniform layer by magnetron sputtering whereas coatings produced by a chemical deposition process are not continuous.

Prediction of photocatalytic air purifier apparatus performances with a CFD approach using experimentally determined kinetic parameters

An original methodology to predict space–time concentration distribution of VOC in an enclosed space where a photocatalytic air purifier apparatus is placed is herein presented. This apparatus is specially designed for indoor air treatment. Intrinsic kinetic parameters are first determined in a perfectly mixed batch reactor allowing a direct access to chemical reaction rate with a few experiments. Computational fluid dynamics (CFD) is then used to model fluid flow in the room and calculate space–time concentration of VOC by setting chemical reaction rate as a boundary condition based on kinetic parameters determined in the batch reactor. Experiments and modelling are performed using acetaldehyde which is a common indoor volatile organic compound and titanium dioxide thin film coated on steel performed by a PVD method. Remediation of acetaldehyde is investigated at low concentration levels, in the low ppm range. Prediction of acetaldehyde removal in the enclosed space is then compared with experimental results allowing validation of the methodology.

Surface Properties of MoN Coated Engine Piston Rings

Abstract This paper presents an experimental investigation of surface behaviours of compression ring coated with molybdenum nitride (MoN) of a diesel engine. In the experiments carried out, the ring surface of a four stroke diesel engine was coated with MoN — a ceramic material with a thickness of 2.0 ± 0.3 μm — using the arc PVD method. Initially, the test engine MoN coated ring was tested for a while with a load of ½. Then, the same engine without a MoN coating was tested under the same conditions. Analyses of microhardness and SEM were carried out in order to examine surface characteristics of ring. The results show less deformation and fewer scratches due to wear on the MoN coated ring as compared to the uncoated one. We conclude that coating the ring surface of internal combustion engines with MoN contributes to longer life for the ring, and thus the engine, by decreasing the mechanical wear caused by friction.

Effect of Heat Treatments on the Structural and Mechanical Properties of Ti Thin Films Deposited on Steel Substrates by PVD Method

Titanium carbides are well known materials with great scientific and technological interest. The applications of these materials take advantage of the fact that they are very hard, refractory and that they have metallic properties. In this work, we have studied the influence of the heat treatment temperatures (400-1000°C) on the interaction between the titanium thin films and steel substrates. Steel substrates, 100C6 type (AFNOR norms) containing approximately 1 wt % of carbon were coated at 200°C with titanium thin films by magnetron sputtering. The samples were characterized by X-ray diffraction (XRD) and Auger electron spectroscopy (AES). Vikers micro-hardness measurements carried out on the annealed samples showed that the micro-hardness increases with annealing temperature, reaches a maximum (3500 kg/mm2), then decreases progressively. The growth of micro-hardness is due to the diffusion of the carbon, and to the formation of titanium carbide. However, the decrease of micro-hardness is associated with the diffusion of iron and the formation of iron oxide (Fe2O3). At higher temperatures, we note the formation of titanium dioxide (TiO2).

Notices on Method of Thickness Evaluation of TiN Layers on Magnesium Alloys

Widely used in mechanics is the method of surface parameters investigation by indentation of some kind of penetrator into test surfaces and registration of the indentation/load dependence through the whole test duration. A small ball made of hardened steel or diamond pyramid, so-called Berkovich pyramid, is used for penetration. An actuator performing the indentation process is used for displacement enforcement as well as for load measurement. Mainly two types of devices are in use: based on piezoelectric effect or purely electromagnetic LVDT. Knowledge about the penetrator tip is essential for the proper evaluation of the measured parameters and knowledge about the actuation method is also desired for better identification of the whole system parameters when using DSP type algorithms at the stage of experimental data elaboration. In this paper we deal with some kind of DSP elaboration of the experimental data. Our attitude is based on successive digital filtration applied to the experimental data as well as to the intermediate stages of calculation, especially for compliance estimation. Different digital filters have been developed and applied to the experimental data. Some conclusions have been taken out due to the precision of the layer thickness estimation based on data obtained by indentation of the investigated surface with a Berkovich pyramid driven by a piezoelectric actuator. The Boussinesq/Sneddon theory has been used as the basis of our analysis. Titanium azide layers imposed on a magnesium alloy have been tested using PVD method. Obtained results especially due to the hardness/indentation plot allow evaluating the layer thickness, which should be also compared with thickness values evaluated by other methods.

Effect of Nb + Ti coating on the wetting behavior, interfacial microstructure, and mechanical properties of Al/Al2O3 joints

The subject of the work was to study the effect of Nb + Ti thin film deposited by PVD method on alumina substrates on the wetting behavior, bond strength properties, and structure of interface in the Al/Al2O3 joints. Applying the sessile drop method, the wetting behavior of molten Al (99,999%) on coated alumina substrates was studied in the temperature range between 953 and 1373 K under a vacuum of 0.2 mPa for 30 min of contact. The sessile drop samples were used to examine the interface structure, shear strength, and interfacial fracture toughness under the concentrated load. The introduction of the thin Nb + Ti film layer of 900 nm thickness: (1) greatly improves the wettability of alumina by molten Al at above 1223 K and the shear strength of Al/Al2O3 joints produced at 1223 K, (2) has positive effect on structure transformation in the interface and leads to fabrication of reliable metal–ceramic joints. Microstructural investigations of the interface indicated that the precipitates of Nb and Ti-rich intermetallic phases were formed at the Al/Al2O3 interface, which influenced strengthening of these joints. Hence a conclusion can be drawn that the interface structure influences the durability increase in Al/Al2O3 joints.

T1601-2-1 金属材料表面の構造寸法がタンパク質吸着に与える影響([T1601-2]マイクロナノメカトロニクス(2))

Influence of structural dimension of metallic surface on protein adsorption was investigated by ultraviolet spectrophotometer. Bovine serum albumin was used for this study. As metal surface, the hole microstructure of the column is fabricated by the photolithography technology and metal film on the surface microstructure was formed by PVD method. The kind of metal was titanium and gold, and the diameter of the hole was 10μm, 5μm, 2μm, respectively. As a result, the diameter of hole structure on metal surface influenced the protein adsorption, and it was found that the total of circumference length of hole influenced greatly. Therefore, to increase amount of protein, it is thought that the hole diameter brings it close to the grain diameter of the protein, and structural number for each unit area should be increased.

Structure, mechanical properties and corrosion resistance of PVD gradient coatings deposited onto the X40CrMoV5-1 hot work tool steel substrate

This paper presents research results on the structure, mechanical properties and corrosion resistance of TiAlN, TiCN and AlSiCrN gradient coatings deposited by PVD methods on the X40CrMoV5-1 steel substrate. The coatings demonstrated columnar structure as well as good adhesion to the substrate, the latter not only being the effect of adhesion but also by the transition zone between the coating and the substrate, developed as a result of diffusion and high-energy ion action that caused mixing of the elements in the interface zone. The critical load LC2 lies within the range of 46-59 N, depending on the coating type.

Structure, mechanical properties and corrosion resistance of nanocomposite coatings deposited by PVD technology onto the X6CrNiMoTi17-12-2 and X40CrMoV5-1 steel substrates

This article presents the research results on the structure and mechanical properties of nanocomposite coatings deposited by PVD methods on the X6CrNiMoTi17-12-2 austenitic steel and X40CrMoV5-1 hot work tool steel substrates. The tests were carried out on TiAlSiN, CrAlSiN and AlTiCrN coatings. It was found that the structure of the PVD coatings consisted of fine crystallites, while their average size fitted within the range 11–25 nm, depending on the coating type. The coatings demonstrated columnar structure and dense cross-sectional morphology as well as good adhesion to the substrate, the latter not only being the effect of adhesion but also by the transition zone between the coating and the substrate, developed as a result of diffusion and high-energy ion action that caused mixing of the elements in the interface zone. The critical load L C2 lies within the range 27–54 N, depending on the coating and substrate type. The coatings demonstrate a high hardness (~40 GPa) and corrosion resistance.

Study on the Si penetration into Fe sheets using PVD method and its application in the fabrication of Fe-6.5wt.% Si alloys

Abstract FeSi (12 wt.% Si) and Si were alternatively deposited on pure iron (Fe) substrates by direct current magnetron sputtering. Subsequent annealing in vacuum at 1150–1190 °C results in penetration of Si into the substrate. Cross-sectional microstructure and Si concentration were investigated by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The penetration mechanism is found to depend greatly on Si amount in the as-deposited films. When FeSi/Si/FeSi/Si/FeSi was deposited on the Fe substrate, the Si penetration is controlled by phase-boundary migration, while a diffusion-controlling penetration is observed in FeSi/Si/FeSi deposited samples. Fe-6.5 wt.% Si sheet with thickness of 0.35 mm is obtained through the deposition of FeSi/Si multilayer on a Fe-3 wt.% Si sheet together with subsequent annealing at 1180 °C for 2 h.

Cubic boron nitride based metastable coatings and nanocomposites

Various PVD and plasma-assisted CVD methods presently used for the deposition of cubic boron nitride (c-BN) thin films demand adequate conditions relating to ion bombardment of growing films, growth temperature, film stoichiometry, etc. The deposition conditions, often appearing rather apparatus-dependent, can be well categorized according to the fundamental parameters of bombarding ions as well as condensing neutral particles, including their energy and flux ratio, and a few of others like ion mass and incident angle. According to these parameters, various surface kinetic processes and their consequences are discussed particularly in connection with the resulting film phases and stress. Typical c-BN films are known for their extremely high compressive stress and poor adhesion as a result of intensive ion bombardment during deposition. Individual measures attempting to relieve this detrimental stress are briefly summarized. The present paper focuses on magnetron-sputtered, c-BN-based metastable films and nanocomposite films with considerably reduced internal stress in comparison to the usual “pure” c-BN films. Two examples will be shown, namely c-BN/a-C nanocomposite and c-BN:O metastable films, including their deposition details, structure and composition characterization, and mechanical properties. Also illustrated is a growth scheme tailored for the deposition of thick, adhered, cubic-phase dominated, superhard c-BN:O films above 2µm on silicon substrates.

Observation of magnetic domains in undoped ZnO grains at room temperature

The present study reports the room temperature ferromagnetism in undoped ZnO thin films grown by PVD method. The 500 nm film with small (90 nm) ZnO grains possess isolated magnetic domains with coercivity of 520 Oe. However, long range magnetic ordering with smaller coercivity of 230 Oe is observed for 1000 nm film. The long range ordering is caused by the reduction in domain wall pinning effect due to the presence of bigger (270 nm) ZnO grains. PL measurements show that these grains are semiconducting in nature. Results presented here suggest that oxygen vacancies at the surface may be responsible for the observed ferromagnetism.

Characterization of MoN coatings for pistons in a diesel engine

In this study, the surface of a piston in a diesel engine was coated with molybdenum nitride (MoN) by using the arc PVD method, and its surface behaviour was subsequently analyzed. Analyses of microhardness, SEM, X-ray and surface roughness were carried out in order to examine surface characteristics of pistons. It is found that the hardness of coated piston is 2000 ± 400 HV while hardness uncoated piston 123 HV. The results show less deformation and fewer scratches due to wear on the MoN-coated piston as compared to uncoated one.

Applications of CrAlN ternary system in wood machining of medium density fibreboard (MDF)

Nowadays, medium density fibreboard (MDF) composite wood is more and more used in the furniture industry to replace bulk wood such as oak, beech, etc. Indeed, this material presents good mechanical properties, is easy to machine, homogeneous, exists in different dimensions (thickness, etc.), is cheaper than bulk wood and finally can be covered by an adhesive decorative coat. Nevertheless, even if this material is homogeneous, it is abrasive enough to tend to the breakdown of the conventional carbide tools employed during its routing process. That is why it is necessary to improve the wear resistance of these tools. One solution is to protect them with a hard coating. The present study deals with the development of ternary CrAlN hard layers obtained by PVD method on carbide tools employed in second transformation of wood. CrAlN coatings have been optimized and then applied on carbide tools in routing of three types of MDF: standard, waterproof and fireproof. The aim of these wood machining tests was first to define the ability to be machined of the three kinds of MDF and second to compare the effectiveness of CrAlN coatings during the routing tests of these materials.

Application of Al and Pt nanofilm systems produced by magnetron sputtering for modification of catalytic properties of alumina obtained on ferritic foil

In the process of producing the catalytic systems using the method for oxidation of ferritic foil with a deposited film of catalytic elements, it is important to select the film thickness providing the best activity of the catalytic system. If the film is deposited prior to the process of oxidation, it is expected that during the growth of oxide crystallites, the film will be broken and the maximum dispersion of catalytic elements will be obtained. If the film is formed of aluminium-active elements, it is expected that the oxide hybrid systems with higher activity of catalytic sites will be produced. Experimental investigations presented in this paper were focused on measuring the thickness of Al and Pt nanofilms and (Pt + Al) composites by the X-ray Reflectivity method, produced by the PVD method, and the morphology of oxide films obtained at various periods of oxidation. The catalytic activity of alumina films coated with Al, Pt nanofilms, Pt/Al and Al/Pt laminates and (Pt + Al) composites was compared, and it was found that the systems with Pt films and Pt/Al laminates revealed the highest activity of basic sites.

Efficiency Method to Study the Metal Composition for Hard Materials

It has been progressed to study the effect of the metal composition on the mechanical properties of the hard coating synthesized by the PVD method. In traditional method the film with one metal composition is generally deposited by the alloy cathode with the corresponding metal composition in one running, and thereafter investigated on the mechanical properties. On the other hand, a new efficient method, said as the combinatorial method, was suggested for studying the effect of the metal composition on the film characteristics. In this method, the film with various compositions can be obtained at once in one running. In the present report, the effect of the metal composition on the film hardness and the change of the crystal structure were studied in the Ti-Al-N film prepared by the combinatorial method. In combinatorial method, it was found that the film hardness was rapidly decreased with the deposition of the B4 type crystal. This showed the excellent agreement with the result obtained in the traditional method and the propriety of this combinatorial method was proved in the range of the study about the mechanical property of Ti-Al-N film synthesized by the unbalanced magnetron sputtering.