Cathodic Arc Ion Plating Process Research Articles

BGA cutter improvement utilizing nano-TiAlN coating layers synthesized by cathodic arc ion plating process

Ti/Al targets with various concentration ratios, Ti 0.75Al 0.25, Ti 0.66Al 0.33, Ti 0.5Al 0.5 and Ti 0.33Al 0.66 were used in a filtered cathodic arc ion plating system (FCAIP) to deposit the multilayer TiAlN films on Si wafer substrates and WC cermet ball grid array (BGA) cutters at various modulation wavelengths. Transmission electron microscopy (TEM), nanoindentation and BGA router were used to evaluate the characteristics of TiAlN layers and the performance of BGA cutters. TEM analysis revealed that the modulation wavelengths of deposited layers are less than 10 nm at various rotation speeds in FCAIP chamber and the crystal structure of TiAlN layer with the maximum hardness is NaCl-B1 structure using the Ti 0.5Al 0.5 target. The maximum hardness of multiple TiAlN layers measured by nanoindentation was 43 GPa, while the TiAlN monolayer exhibited the maximum hardness of 30 GPa in the same chamber. The TiAlN-coated BGA cutter deposited at the optimized condition exhibited a twice longer life and a higher machining speed in comparison with the conventional cutter.

磁場フィルター型ＡＩＰ法で形成したステンレス鋼窒化膜の構造および機械的特性

Nitrogen-containing stainless steel coatings were synthesized from different stainless steel targets (SUS 304, 310 S) by a cathodic arc-ion plating process, using two types of arc-cathode, namely, conventional and magnetically filtered cathodes. The effects of the cathode type, target material and process parameter on the structural, compositional and mechanical properties of coatings were investigated. From X-ray diffraction analysis, coatings deposited by a magnetically filtered cathode showed a new crystal structure, which could be identified as a cubic type zinc-blend or rock-salt structure, whereas the coating deposited by the conventional cathode was a mixture of nitrogen supersaturated fct (face centered tetragonal) type gamma Fe-N phase and Fe3N. The relationship between nitrogen partial pressure (PN2) and nitrogen content in the coating showed quite different behavior depending on the cathode type used. For the conventional cathode, the nitrogen content increased gradually as the PN2 increased from 0.8 to 2.7 Pa and reached approximately 30mol% at the highest PN2. However, using a magnetically filtered cathode, the nitrogen content was about 40 to 50 mol%, at a pressure range of 0.7 to 1.0 Pa. The change in the crystal structure, depending on the cathode type, was considered to be primarily due to the difference of the nitrogen content in the coatings. It was concluded that using the magnetically filtered cathode, ionization of the gaseous species in the process chamber could be enhanced due to the longer electron path from the cathode to the anode, resulting in enhanced reactivity of nitrogen with metallic elements.

Characterization of WC–CrAlN heterostructures obtained using a cathodic arc ion plating process

New WC–CrAlN heterostructure films were deposited on Si wafer and S45C steel substrate by a cathodic arc ion plating (CAIP) process. The Al concentration and bilayer repeat period (λ; 2–10 nm) were controlled to obtain a nano-layered structure. We have characterized our samples using X-ray diffraction (XRD), cross-sectional transmission electron microscopy (TEM) and electron diffraction patterns. Mechanical properties of the WC–CrAlN films were characterized using nano-indentation tests, residual stress evaluation and scratch testing. The microhardness of WC–CrAlN films was in the range of 30–43 GPa. The residual stress was reduced below 2 GPa and the adhesion strength obtained was approximately 50 N by alternative deposition of heterostructure (WC–CrAlN) and buffer (WC–Cr) layers.

Structure and properties of WC–CrAlN superlattice films by cathodic arc ion plating process

New WC–CrAlN superlattice films have been deposited on Si(100) substrate using a cathodic arc ion plating system. A substrate holder was rotated with a range from 1 to 12 rev./min to control the thickness of layered structures, and on arc power density of Al cathodes was controlled to change the Al concentration in the film. The microstructure and mechanical properties of the film depend on the superlattice period (λ) and Al concentration. The chemical composition was evaluated by glow discharge optical emission spectroscopy (GDOES). Using X-ray diffraction analysis (XRD), it is observed that the preferred orientation of microstructure is changed according to the superlattice periods (λ) and Al concentration. Through transmission electron microscope (TEM) analysis, the microstructure and superlattice period (λ) of the WC–CrAlN superlattice film were confirmed. The hardness of the deposited film was evaluated by a nanoindentation test. As a result of the nanoindentation test, the hardness of WC–CrAlN superlattice film gained approximately 40 GPa at the superlattice period (λ) of 7 nm. The structure of WC–CrAlN superlattice film was transformed from dense columnar structure to a nanocomposite structure.

Industrial application of WC–Ti (1− x) Al xN nanocomposite films synthesized by cathodic arc ion plating process on a printed circuit board drill

New WC–Ti (1− x) Al x N nanocomposite films were synthesized on Si wafer WC–Co substrate by cathodic arc ion plating. A rotating substrate holder operated at 6 rev./min was used to obtain a layered structure, and the arc power density of Al cathodes was controlled for the change of Al concentration ( x) in the film. For the evaluation of crystal structure and compounds formation behavior, X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (XTEM) analyses were performed. The microhardness of WC–Ti (1− x) Al x N films was measured at a normal load of 30 mN by a nano-indentation instrument. WC–Ti 0.43Al 0.57N nanocomposite film that revealed the highest hardness and good adhesion strength were applied to a printed circuit board (PCB) drill for the evaluation of the drill's lifetime. As a result of adapting a PCB drill coated with WC–Ti 0.43Al 0.57N film, the lifetime of the PCB drill was improved by more than two times than that of the ordinary one.

The effect of arc ion pre-bombardment on the impact failure of TiN coating on Co-WC

Co-WC is increasingly used for precision dies and punches in semiconductor assembly process. The enhancement of impact resistance of hard layer coatings on Co-WC dies and punches is crucial for the application of hard coatings such as TiN. In this study, Co-WC has been deposited with a TiN film after Ti bombardment at various bias voltages of 0–750 V using the cathodic arc ion plating process. The surfaces' etching morphology and the temperature increase upon pre-bombardment with Ti ion onto Co-WC were evaluated by SEM and in-situ monitoring, respectively. The increase of bias voltage over 500 V significantly induced selective etching of Co and enhanced the substrate temperature higher than 300 °C in 10 min, thereby promoting the formation of a dense TiN film onto it. The prior etching of the surface by Ti ion bombardment with a high bias voltage was very effective in improving the adhesion of the TiN film on Co-WC and therefore reduced plastic deformation and crack density around the indentation area in a Rockwell C indentation test. The impact failure of a TiN coating on Co-WC could be consequently reduced under loads up to 150 N.

The shear impact wear behavior of Ti compound coatings

The failure behavior of Ti compound coatings was evaluated under normal and shear impact conditions at room and elevated temperatures. Monolayers and combined multilayers of TiAlN and TiAlCN were deposited onto high speed steel by a cathodic arc ion plating process. The shear impact loading mode was obtained by rotating the coated disk specimen at a speed of 0.8 m s −1 under repetitive normal impact loading of 10 N using a CoWC ball indentor with a frequency of 5 Hz. The impact resistance under normal impact loading appeared to be higher in the order TiAlN, TiAlN/TiAlCN and TiAlCN in accordance with the adhesive strength measured by HRC indentation tests. Meanwhile the addition of shear force during repetitive normal impact loading by specimen rotation reduced significantly the failure resistance of all the films, both at room temperature and 600°C, with a change in failure mode. It was observed through progressive failure analysis with increasing repetitive loading cycles that the failure under shear impact loading was accelerated owing to the promotion of crack formation as well as laminated fragmentation by increasing tensile and shear stresses at the ball trailing zone resulting from tracking forces during repetitive instantaneous impacting and sliding. The propensity for failure became more severe owing to substrate softening for all the coatings as the temperature increased to 600°C.

Correlation between three-body wear and tribological characteristics of titanium nitride, titanium carbonitride and titanium carbide coatings

The tribological characteristics of the TiN, TiC and Ti(C,N) coatings related to three-body abrasions were studied in this work. Eight types of coating films were deposited by means of the cathodic arc ion plating process by varying the mass flow rates of nitrogen and acetylene gases during the coating processes. The lower specimens were coated by the titanium film as the underlayer and the TiN, TiC or Ti(C,N) film as the top layer. The influences of the three-body wear on various parameters, including mean friction coefficient, the fluctuations of friction coefficient, electrical voltage and specimen temperature, were discussed. The fluctuation intensity in the friction coefficient curve is affected by the mean size of the wear debris entrapped between two rubbing surfaces. Three-body wear is more often produced in the ceramic coatings which was operated at a lower specimen temperature or at a higher sliding speed while the specimen temperature was still low. If the specimen temperature was raised high enough, the three-body wear was gradually diminished because brittle fracture was impeded by the thermal effect. Wear mechanisms occurring in the Ti(C,N) coatings are much dependent upon the operating conditions and less affected by the change in the chemical composition of ceramic coating.

The tribological characteristics of titanium nitride, titanium carbonitride and titanium carbide coatings

The tribological behaviors of TiN, TiC and Ti(C,N) coatings prepared by differing mass flow rates of nitrogen and acetylene during the coating process are studied in this work. The lower specimens were coated with titanium film as the underlayer and with TiN, TiC or Ti(C,N) film as the top layer. They were deposited by the cathodic arc ion plating process. The chemical compositions of eight types of ceramic coatings were determined by the wavelength-dispersive X-ray analysis. The influence by changing the mass flow rate ratio of N 2 and C 2H 2 gases on specimens tribological behavior, microhardness, coating morphology, and adhesive strength was investigated. The three-body abrasive wear more often appeared at the temperatures that the ceramic coating was not yet softened by the frictional heat. Increasing the mass flow rate ratio of the acetylene gas in the coating process is favorable for more ions to react with the titanium, thus resulting in noticeable rises of the C/Ti atomic ratio; conversely, it is disadvantageous for nitrogen ions to react with the titanium. The wear rate of the lower specimen with the TiN film is the lowest of the three kinds of ceramic coatings; however, its friction coefficient is relatively higher than that of the TiC film.

Synthesis of wear resistant compounds by plasma diffusion process

Thermal resistant compound layers have been synthesized on hot working tool steel (H13) through the duplex process by combining metal ion plating and nitrogen plasma diffusion at elevated temperatures of 550–950 °C. Ti and Al layers were deposited by the cathodic arc ion plating process in three different modes which were Ti single layer, Ti/Al and Ti/Al/Ti and then subsequent nitrogen plasma diffusion treatment with intense plasma heating through hollow cathode discharge effect. Plasma diffusion of Ti and Al films on the steel substrate in the temperature range 550–950 °C produced nitride compounds of TiN and Ti 2AlN as well as various intermetallic compounds of Fe 3Al and Fe 2Ti at the surface and interface region. The formation of mixture compounds highly enhanced surface hardness up to 2800 HK (0.25 N). High temperature wear resistance also greatly increased in the temperature range 300–600 °C due to the layer formation of thermal resistant compounds. Compound formation features and high temperature wear behaviors are analyzed using XRD, EDS, and microstructural observation.

The tribological characteristics of titanium carbonitride coatings prepared by cathodic-arc ion plating technique

The tribological behavior of specimens coated by two layers, titanium carbonitride film as the top layer and titanium film as the underlayer, is studied in this work. The coating layers were deposited using the cathodic-arc ion plating process (CA) technique. Experiments were carried out on a wear test machine using a thrust-washer adapter to simulate the surface contacts between the steel ring (the upper specimen) and the titanium carbonitride coated washer (the bottom specimen). We address the influence of the thickness of the two coating layers on tribological behavior, the wear mechanism, specimen hardness, coating morphology, and adhesive strength. Higher measured values of electrical voltage are always obtained in the specimens with lower adhesion strength. A thin titanium carbonitride film with a thick titanium underlayer decreases the adhesion strength, resulting in a higher wear rate. The effect of surface morphology on specimen wear rate is dependent upon the sliding speed and the coating thickness. When the specimen's sliding speed is raised, both the wear rates and the friction coefficients decrease significantly.

The tribological characteristics of titanium nitride coatings. Part I. Coating thickness effects

The tribological behavior of specimens coated by two layers, titanium nitride film as the top layer and titanium film as the underlayer, is studied. The coating layers of the bottom specimens were deposited using the cathodic arc ion plating process technique. Experiments were carried out on a wear test machine using a thrust-washer adapter to simulate the surface contacts between the steel ring (the upper specimen) and the titanium nitride coated washer (the bottom specimen). We address the subject about the influence of the thickness of the two coating layers on tribological behavior, wear mechanism, specimen's hardness and adhesive strength. A thin titanium nitride film in combination with a thick titanium film attenuates the adhesive strength, resulting in a significant increase in wear rate. The influence of the titanium nitride or titanium thickness on the friction coefficient is quite limited at higher sliding speeds. The specimen's hardness is increased by thickening the titanium nitride layer, but is lowered by increasing the titanium thickness. When the specimen's sliding speed is increased, both the wear rates and the friction coefficients show significant decline.

Parameter Optimization for the Arc-Adlc-Deposition Process

ABSTRACTOne method used by the industry for the deposition of thin carbon films is the dc cathodic arcion plating process. The evaporation of a graphite cathode by a high energy arc beam results in the production of carbon atoms, ions and macroscopic graphitic fragments. All these particles influence the film growth, the structure and therefore the film properties. The incorporation of the macroscopic graphitic fragments can be avoided by the use of mechanical or magnetic filters in front of the cathode. These filters prevent the direct bombardment of the substrates with particles. This particle separation involves decreased substrate current densities and this means lower deposition temperature (< 200°C) and growth rates. With the addition of inert (argon) and reactive gases (nitrogen and methane) and the use of a bias voltage on the substrate economical deposition rates of 2-4 μm/h and good adhesion on various materials can be reached.This paper describes the production of amorphous hydrogen and hydrogen-free carbon films by a modified cathodic arc evaporation process using a simple mechanical filter for particle reduction. It shows the influence of some process parameters on the optimization of the process stability and process efficiency. Some characteristic properties of these coatings are shown by an example.

Properties of TiN, ZrN and ZrTiN coatings prepared by cathodic arc evaporation

The paper is devoted to the reactive deposition of TiN, ZrN and ZrTiN coatings prepared by a cathodic arc ion-plating process. Cathodes made of Ti and Zr were evaporated in an N 2 atmosphere. ZrTiN coatings were created by simultaneous evaporation of both Ti and Zr. Typical operation characteristics of individual depositions are presented. Special attention is devoted to the coating properties, namely to the film microstructure, surface morphology, phase and chemical composition, microhardness and adhesion.