PVD Technology Research Articles

Ti-N-C Films Deposited by Ion Beam Assisted MF Twin Targets Unbalanced Magnetron Sputtering

Using Hall ion source assisted MF twin targets unbalanced magnetron sputtering, series of Ti/TiN, Ti/TiN/Ti(C,N) and Ti/TiN/Ti(C,N)/TiC hard anti-wear films are deposited on different materials like stainless and high speed steels by changing atmosphere, bias mode, sputtering and ion beam assisted currents. The color, crystal structure, hardness and binding force of film are tested and analyzed, respectively. Experimental results show that color of film is sensitive to atmosphere, slight change of atmosphere can influence the coating’s color seriously. The preferred orientation of Ti(C,N) films prepared by MF twin targets unbalanced magnetron sputtering has no obvious change compared with the film deposited by other PVD technologies. The substrate material has great influence on film’s hardness, binding energy and surface modification. The application of Hall current can effectively improve the binding force between film and substrate.

Design of wear and corrosion resistant PVD‐coatings for magnesium alloys

AbstractAlthough magnesium alloys became popular in the first half of the 20th century, the bad corrosion properties prevented their breakthrough in industrial mass production. Since the technology for the production of high purity alloys was introduced in the 1970s, magnesium alloys became more and more in the focus of industrial attention. Today magnesium alloys are state of the art in structural parts in automotive industry. Despite its outstanding properties like good castability, low density and nearly unlimited availability the negative aspects like weak corrosion and wear behaviour still limit the application of magnesium in industry [1]. So, the only economic solution is the deposition of a coating or a suitable surface treatment which provides both, wear and corrosion resistance. Today, plasma electrolytic anodisations are state of the art [2–5]. They provide acceptable corrosion resistance and protect the magnesium from mechanical damage due to their high hardness. On the other hand, their high porosity limits their use in combination with electrochemically noble materials, leading to galvanic corrosion [6]. In addition, the high surface roughness of the plasma electrolytic anodisations restricts their use in tribological applications, particularly under dry sliding conditions [7].On the other hand, due to the high life time recommendations the application of magnesium in the automotive industries motion component field is a long term process. Nevertheless, there is a quite high industrial interest to apply magnesium in the motion component field in consumer applications like do‐it‐yourself or gardenig. Some examples are motor components of lawnmovers, motor saws or drills. Especially for these fields of application there are quite high demands on the corrosion properties due to undefined storage and the conditions during usage.In order to achieve smooth surfaces with high quality, the PVD technology moves into the centre of interest. Since the 1980s PVD coatings are well established and widely used for different industrial applications, mainly for steel and tool coatings. The authors were the first who carried out serious studies on the development of PVD coatings for magnesium alloys since 1999 [6, 7].The extensive research activities lead to the recent development of a coating system, which provides both, good wear properties as well as good corrosion behaviour.

An investigation of the electrochemical properties of PVD TiN-coated SS410 in simulated PEM fuel cell environments

Bipolar plates are a key component of PEM fuel cells, and they constitute a large portion of the weight and total cost of a fuel cell stack. In order to reduce both the cost and weight of the bipolar plates, considerable attention is being paid to developing metallic bipolar plates to replace non-porous graphite. In this study, TiN was coated on a martensitic stainless steel (SS410) using a PVD technology (plasma enhanced reactive evaporation) to increase the corrosion resistance of the base metal. XRD, SEM, EIS and potentiodynamic tests were used to characterize the TiN-coated SS410. In order to investigate the suitability of these coated materials as the anodes and cathodes in a PEMFC, potentiostatic tests were conducted under both simulated cathode and anode conditions. The simulated anode environment was - 0.1 V vs SCE purged with H 2 and the simulated cathode environment was 0.6 V vs SCE purged with O 2 . The dense TiN coatings formed on SS410 much improved the corrosion resistance of SS410 and, thus, these coated materials could potentially be used in PEMFCs as a bipolar plate material provided they also satisfy the other physical and mechanical property requirements such as interfacial contact resistance, light weight, high mechanical strength and manufacturability.

Investigations of the polyaniline and nafion bilayer sensor structure in SAW system

Presented here are the preliminary results concerning an investigations of a novel bilayer sensor structure of polyaniline and Nafion as a toxic gas sensors in a Surface Acoustic Wave system. The investigations were performed with different concentrations of the various toxic gases like SO 2 , CO, H 2 S and ammonia (NH 3 ) in synthetic dry air. The prototype polyaniline and nafion bilayer structure has been manufactured by two deposition technologies: 180 nm of PANI by PVD technology and thin Nafion film by spin coating technology and specific process of annealing. A good interaction with various concentrations of ammonia for the bilayer structure (PANI film with Nafion) has been observed.

New approaches to plasma enhanced sputtering of advanced hard coatings

PVD coatings and cutting tool materials experienced a rapid development in the past due to the increased demands of modern, innovative HPC (High Performance Cutting) production processes. The development of new materials progressed so rapidly that it is partly not known, how these materials can be economically processed with respect to measures of reducing costs and thus increasing productivity. In order to meet the different requirements a range of developments have been brought forward in the area of coating technology. Al 2O 3 was and still is an important component of conventional coatings. Especially the different crystalline modifications synthesized by CVD have gained considerable economic significance. Distinct chemical resistance, higher hot hardness and less interaction with almost all production relevant materials than most hard coatings are the main success factors of Al 2O 3 films. Within the first step the plasma enhanced PVD technology for the deposition of ternary coatings with higher aluminum content was developed. These films continuously generate a protective crystalline alumina layer at elevated temperatures. In addition to RF- and DC-sputter sources, pulsed plasma sources are gaining increased attention in sputter technology. This interest is driven by the significantly enhanced ionization of pulsed plasmas as compared to conventional DC and RF techniques. Using highly ionized plasmas the High Ionization Sputtering (H.I.S.) and the High Ionization Pulsing (H.I.P.) processes have been developed to deposit a novel grade of high performance hard coatings, the supernitrides. The present paper provides a survey of latest approaches to plasma enhanced sputtering and related coating systems, with regard to the demands of high performance applications.

Estudio para la recuperación de herramientas recubiertas con nitruro de cromo mediante ensayos galvanostáticos

The improvement of the corrosion, wear and tribological behaviour by searching for new materials has entailed a greater expansion of PVD technology. Introduction of PVD systems in the industry is a real fact because this technique has been able to develop coatings whose response for many applications goes beyond used them until now. However the evolution of this technology requires minimize the economic costs in order to be a competitive process. A way to achieve this objective consists on recover the tool when the life time of the coating has finished or when deposition process has failed. Bringing this idea in the industry requires the stripping methods’ development due to surface’s tool must be clean —without coating’s remainders—, before a new deposition process. Current work shows galvanostatic stripping of chromium nitride coating deposited by two different PVD techniques: cathodic arc and magnetron sputtering. The electrochemical method has exhibited more advantages than chemical methods reported in literature, such a high sensitivity to detect final point of CrN coating stripping, capability to determinate structure of the coating —number of coatings, chemical composition, thickness…—, short times of the process and minimum damage on the substrate. These entire characteristics do possible think about a new deposition process on the stripped tool.

AlTiN - a universal coating for different applications: from dry cutting to decorationAlTiN - Die Universal-Beschichtung für eine Vielzahl von Anwendungen: von Trockenzerspanung bis Dekor

AlTiN coatings were developed over the last 10 years mainly for cutting applications. Besides composition and architecture of AlTiN coatings also PVD technology based on the reactive cathodic vacuum arc evaporation was permanently improved in view of various application fields. Different basic processes were developed in appropriate PVD units to cover wide spread process demands. Both, low temperature processes for decorative coatings including deposition on galvanized plastics as well as high temperature processes for cemented carbide tools can be realized with optimized processes. This paper presents PVD units and selected applications like gear hobs, broaches, ball end mills, cutting blades, forming tools and decorative coatings.

A new generation of filtered arc sources for ultrathin top coats on magnetic hard disks

Filtered cathodic arc deposition is a promising candidate as an industrial PVD technology for the deposition of challenging films in microelectronics and microsystems. This technique has proven its superiority of depositing high quality films compared to conventional arc applications in numerous laboratory tests. In advanced sources, the number of droplets is reduced to less then 1 millionth corresponding to less than 1 μm size particle/cm 2, good enough for many advanced tool coatings but still insufficient for such highly demanding applications as the deposition of the top coat on a hard disk. In the present paper, recent improvements of the filtered high current pulsed arc (Φ-HCA) technique are described, resulting in a nearly complete droplet elimination to only a few 10-nm size particles/m 2. With the Φ-HCA-source, we are able to produce pinhole-free corrosion protective carbon films with thickness down to 1.7 nm. The thickness profile and uniformity on disk is adjustable by a magnetic field array. The deposition rate is 3–5 nm/s; therefore, the coating time is below one second per disk. The magnetic layer is left undamaged during the Φ-HCA deposition process. These aspects are very important for industrial disk production efficiency. Strong particle reduction due to a magnetic filter tube is confirmed by repeatable glide tests. In several important tests, we showed that the Φ-HCA source is capable of producing carbon layers within a realistic disk production environment with a yield of approximately 93%, which proved to be comparable to current industrial technology. Apart from the hard disk coating, the current Φ-HCA source is a carbon deposition technique with high potential for many other industrial applications, e.g. for acoustic sensors, selective ion-beam mask-layer and applications needing thermal conductivity layer, etc.

Electron beam-based PVD technologies offer new choices to aerospace engineers

Electron beam-based PVD technologies offer new choices to aerospace engineers

セラミック硬質被膜の弾性定数と残留応力

Recently, for the purpose of increasing the wear resistance of tools, the hard ceramics, TiC or TiN, are coated by the PVD technology on the surface. The physical properties of such deposited thin films differ from those of the bulk materials.In this study, the TiC or TiN films deposited to various thickness on the stainless steel substrate are prepared. The elastic constants of each film in the single and double layers are measured by the mechanical and the X-ray diffraction method. It is found that the elastic constants measured by the X-ray diffraction method are higher than that by the mechanical method. And then, the elastic modulus and compressive residual stress of each layer in the double-layer coatings are somewhat lower than that of single-layer coatings because of decrease in the texture and the internal strain.

Innovative steel strip coatings by means of PVD in a continuous pilot line: process technology and coating development

Based on PVD coating of already conventionally zinc-coated steel strip novel approaches to highly corrosion resistant zinc alloy coatings have been developed on a laboratory scale. In this paper, the successful up-scaling of such an approach to a continuous pilot line with line speed up to 60 m/min and strip width of 300 mm is reported. The PVD technology of the pilot line comprises different plasma cleaning processes, thermal evaporation by means of radiation heating as well as electron beam evaporation. First results of coating development by means of evaporating thin additional layers of different metals on already conventionally zinc coated steel strip will be presented.

Structural investigation and wear resistance of submicron TiN coatings obtained by a hybrid plasma immersion ion implantation process

The ever increasing demands for high precision machining and increased cutting performance, in terms of cutting speed and lifetime, require wear resistant tools of large dimensional accuracy that have very sharp cutting edges. All these requirements cannot be fulfilled by the classic PVD and CVD technologies because they result in rather thick overlay coatings. In this report, first experiments are presented on a hybrid plasma immersed ion implantation process (PIII) for depositing thin TiN coatings on hardened and annealed high speed steel or cemented carbides. The layers were produced using a d.c.-cathodic arc source with a titanium cathode and a nitrogen feed gas. As the cathodic arc generates additional to the metal plasma, a large amount of liquid metal droplets, the plasma was guided to the samples through a 90° magnetic bending field avoiding the deposition of droplets on the samples. The obtained layer thickness was below 1 μm for deposition times of 2 min. To improve the adhesion of the deposited layers on the substrate materials, sputter cleaning by energetic ions was used during the initial phase of the process. Negative high voltage pulses in the range from zero to 5 kV have been applied to the samples during the deposition. The effect of the energy of these ions on the coating structure was also investigated by SEM, TEM and XRD. Mechanical and functional properties were investigated by hardness measurements and fretting wear tests, respectively. Finally, cutting performance tests of PIII-treated drills were performed, revealing that a 0.8-μm thick TiN PIII-coating increased the lifetime of the drills by a factor of 2.5.

New coatings on metal sheets and strips produced using EB PVD technologies

PVD coatings deposited by electron beam (EB) evaporation on large metal sheets and metal strips are discussed and have been used for many years. Recently developed plasma activated technology has opened up new potential applications. The new coatings produced by EB PVD represent an outstanding supplement to existing products. It is verified that the deposition costs are low enough in comparison to competitive technologies.Dense Ti layers are produced with high deposition rates up to 1000nms−1 by EB evaporation in combination with effective plasma activation by a spotless arc (SAD-process). The corrosion resistance of the coatings deposited with this SAD process and an additional bias voltage can be drastically improved in comparison to deposition without plasma activation.Aluminum oxide coatings were deposited by reactive EB evaporation at deposition rates between 50 and 100nms−1. The influence of plasma activation using a hollow cathode low-voltage electron beam (HAD process) on the structure and properties of Al2O3 coatings have been investigated. It could be shown that the coatings deposited with the HAD process have a drastically increased hardness, higher density and an improved chemical stability in comparison to the coatings deposited without plasma activation.Stone-blasting resistance can be improved and good formability of galvanised steel can be maintained by a thin Fe layer. The Fe layer is deposited by high rate EB evaporation and then via a subsequent annealing process an intermetallic compound top layer is created.

PVD coating of plastic webs and sheets with high rates on large areas

For many product applications, plastic material needs to be coated with transparent oxide layers to obtain the required properties like permeation barrier, abrasion resistance, anti-reflection and defined optical transmission for example. First of all, outstanding properties of coated material are needed in comparison to competitive technologies. Beyond this, acceptable costs for the market are decisive for the introduction of PVD technologies into production. This paper gives an overview of the great variety of applications.The deposition rate has a strong influence on coating cost: the higher the rates, the lower the cost.High rates, especially for deposition of oxides, are often considered as being linked to poor layer quality. Plasma activation of vapor is one method to obtain high rates and acceptable properties. Hollow cathode activated deposition process (HAD) and pulsed magnetron sputtering (PMS) will be explained. Results concerning layer properties will be depicted. An outlook to the future will be derived.

Mid frequency sputtering with TwinMag ®-a survey of recent results

Since DC magnetron sputtering was introduced for the manufacturing of optical thin film systems on large area glass substrates, coating processes have suffered from poor long term stability and low deposition rates. After long years of intensive development work, today AC (mid frequency) powered twin magnetron arrangements are capable to overcome these drawbacks. During the past two years much data has been collected on AC reactive deposition of SiO 2, Si 3N 4, Ta 2O 5, TiO 2, SnO 2, and ZnO. SiO 2 and TiO, the most prominent candidates for optical interference coatings, can be deposited on large scale at rates exceeding 5 nm/s in a stable continuous process for more than 300 hours. The deposition rates for SnO 2 and ZnO are in the range of 10 nm/s. High density, low surface roughness and very good optical properties of all deposited materials result from bombardment of the growing film by a high flux of energetic ions. The paper gives a survey on recent results with special emphasis on TiO 2 and SnO 2 layers. New applications like antireflective-antistatic coatings are presented. Enhanced performance and high resistance against environmental attacks indicate that AC sputtering will play a major part in the future of PVD technology.

Magnetron sputtering of films with controlled texture and grain size

Magnetron sputtering of thin films is a strongly developing field of PVD technologies. This paper reviews the recent progress in sputtering of films with controlled texture and grain size using the ion bombardment of growing films and/or the mixing process, i.e. an incorporation of one or several additional elements into a base material. Special attention is devoted to the formation and properties of nanocomposite coatings with grains smaller than 100 nm. New physical properties of these materials, not attainable in polycrystalline films with grains greater than 100 nm, are outlined. The concept of attaining a new generation of hard nanocomposite coatings with high toughness is also described.

CCVD: Low-Cost Vapor-Deposition of Thin Films in Open Atmosphere

AbstractThe new, patented Combustion Chemical Vapor Deposition (CCVD) process holds promise for low cost, high throughput manufacturing of thin film ceramic coatings with composition and microstructure tailored for specific applications in electronic, optic, anti-corrosion and anti-wear applications. The flame-based CCVD process is an open-air, non-vacuum, environmentally friendly process with the ability to produce coatings of equal or superior quality to those produced by conventional vacuum-based methods. Capital and operating costs for CCVD coating systems are significantly lower than, for example, conventional CVD and PVD technologies. As an open-atmosphere process, ccvD can be easily implemented in a continuous production line environment, avoiding the need for vacuum load-locks. MicroCoating Technologies has used CCVD to deposit over 60 different inorganic materials onto a variety of substrates ranging from metals and polymers to ceramics. Multi-layered films of complex composition have been achieved with excellent stoichiometric control. We review the CCVD process and characteristics of representative coatings

Zinc coatings on steel produced by ion beam assisted deposition

World-wide, only about 30% of cold-rolled products are coated by conventional methods such as hot-dip galvanising and electrodeposition. The demand for coated steel strip is expected to increase in the next few years and it has been demonstrated that dry PVD technologies can be applied continuously or in a semi-continuous way to produce corrosion-resistant coatings with excellent properties and performance. PVD technologies are also attractive because of reduced environmental constraints compared with conventional methods. Ion beam assisted deposition (IBAD), a relatively new PVD technique, offers the possibility of controlling process parameters independently, and can produce coatings with tailored properties. The aim of this work has been to evaluate the use of IBAD as a prospective method to produce Zn coatings on steel strip. Zinc coatings were deposited by IBAD onto 1 mm IF-steel sheet, at a thickness of approximately 5 μm. Various angles (10 °–50 ° to the ion beam), evaporation rates (1–3 nm s −1) and ion beam energies (500–1000 eV) were selected, while the beam intensity was kept constant at 25 mA. This was to maintain the I/A arrival ratio at a sufficiently low value to obtain good deposition rates when taking into account sputtering effects. A bending test was conducted to test the formability of the coating. Any cracking or delamination that occurred was observed under an optical microscope and a chemical test was used to determine the amount of revealed substrate. This test showed the lack of interconnected pores in the Zn coatings. Furthermore, all IBAD films showed good adhesion and formability with no signs of delamination. Topographical observation of the coatings was undertaken using SEM, which was also used to study the coating thickness and uniformity. These observations showed the deposited coatings to be uneven and of widely varying thicknesses. These variations are discussed in terms of the effects of sputtering and evaporator-substrate distance. From SEM micrographs it could be seen clearly that ion bombardment during deposition influences the structure of the produced film, changing the structure from a highly columnar growth to a fine, even-grained structure. The corrosion resistance was tested using a standard ASTM B117 salt spray test, with a 3.5% NaCl salt solution. This test showed a dependence of the corrosion resistance on the film thickness, with little variations due to the different morphology or microstructure of the films.

Energetic particles in PVD technology: particle-surface interaction processes and energy-particle relationships in thin film deposition

Energetic deposition techniques, including ion beam assisted deposition, ion plating, unbalanced magnetron sputtering, and cathodic-arc deposition, are playing an increasing role in the processing of coatings for mechanical, optical, and electronic applications, and for the protection of surfaces in hostile environments. Advantages of energetic film deposition include low temperature processing, improved adhesion to substrates, production of desired phases or compounds, and control of crystallographic orientation. There are certain fundamental physical processes common to these energetic deposition methods that involve the alloying of elements (ion implantation, condensate and gas adsorption), material removal (sputtering, desorption), collision-induced displacements, collision-stimulated thermal exchange, and collision-induced surface and bulk diffusion. The mechanisms by which these mechanisms affect film formation are under intense investigation. New Monte Carlo and molecular dynamics simulations of the effects of energetic atoms on surfaces as well as experimental investigations revealing relationships between deposition variables and phase formation are contributing to our understanding of thin film growth. This paper covers the above topics by first establishing the ‘ideal’ conditions for deposition of a film, indicates how different deposition processes attempt to approximate these conditions, and reviews known correlations between deposition variables and film characteristics.

Tribological properties of coatings—expectations, performance and the design dilemma

So-called advanced coatings systems produced by the CVD and PVD technologies to enhance the tribological behaviour of engineering artifacts—especially tools and dies—have been available for a number of years and, commonly, excellent end-results are confidently quoted. Critical analysis of published performance data, however, reveals that behaviour may be erratic and irreproducible with ‘well-established simple’ coatings such as TiN even in single layer format. Promising, more novel, coating systems involving alternative compounds in, for example, multi layer format have been identified in the research literature, but their appropriateness to particular needs of industry has to be systematically established. It becomes evident that there is a major lack of understanding of the significance of the physical and mechanical properties of coatings materials in monolithic form, the corresponding values for the same materials as coatings, the reported differences in these parameters and especially their importance, or otherwise, for coated artefact performance. An additional major problem here is the paucity of published data on the large number of compounds—oxides, carbides and nitrides—which, from a materials science point of view, are candidate coating materials. As a result, a systematic approach to the design of the most suitable coating systems—‘fitness for purpose’-is inhibited. Finally, it is believed too little attention has, to date, been paid to the quality assurance dimension in coating design and performance. These matters are illustrated and discussed, and some suggestions for research put forward.