Influence of the bias voltage on the structure and the tribological performance of nanoscale multilayer C/Cr PVD coatings (original) (raw)
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Corrosion and Wear performances analysis of PVD CrMoN/Cr Coatings
Metallurgical and Materials Engineering, 2021
Tools coated CrN based alloys are currently used in several industries for machining and manufacturing but present severe wear, limiting their service life. Seeking an alternative, three CrMoN monolayers (~1-1.8 µm in thickness) coatings varying in the Mo percentage content were elaborated using the RF magnetron cosputtering method. These coatings were evaluated and compared with the alloy currently used (CrN) by electrochemical tests in NaCl solution (stationary and no stationary methods) and sliding wear tests (ball-on-disc configuration) performed at room temperature. The results indicate that the samples coated with CrMoN presented better performance against wear and corrosion than the uncoated sample. Among the coatings, labeled C1 (27Mo at.%) showed the best corrosion resistance as it presents a positive corrosion potential Ecorr. However, the best wear resistance (lowest coefficient of friction) was shown by coating labeled C4 (33Mo at.%). All of the tested specimens underwent abrasive wear in addition to the adhesive wear.
The properties and wear resistance of the CrN PVD coatings
2008
Purpose: The aim of the paper is comparison of the mechanical properties and wear resistance of the monolayer CrN PVD coatings deposited onto heat treated and plasma nitrited X37CrMoV5-1 type hot work tool steel. Design/methodology/approach: The microhardness tests of the PVD coatings were made on the dynamic ultra-microhardness tester. The surfaces’ thopography and the structure of the PVD coatings was observed on the scanning electron microscopy. The evaluation of the adhesion of coatings to the substrate was made using the scratch test. The wear and friction tests were performed on a pin-on-disc device at the room temperature and at the temperature of 500°C. The friction coefficient between the ball and disc was measured during the test. Findings: : In case of the CrN coating deposited onto the X37CrMoV5-1 nitrided hot work steel a very good adhesion has been revealed to the substrate material in comparison to the CrN coating deposited onto the heat treated hot work steel. Taking...
Higher Tool Productivity due to New Generation of PVD Coatings
Vakuum in Forschung und Praxis, 2012
PVD coating technology has seen many new developments in the past few years. HIPIMS+ is an example of these developments with excellent results on tool productivity and lifespan. The technology combines the advantages of arc evaporation with those of magnetron sputtering and results in a dense and defect‐free coating with tuneable residual stress. The coatings have been tested successfully by international tool manufacturers. Additional developments can be seen in DLC coatings and the hydrogen‐free variety ta‐C. These coatings are suitable for low temperature deposition and machining of special materials.
Comparison of the PVD coatings
2009
Purpose: of the paper was comparison of the structure, adhesion and wear resistance of the monolayers CrN and TiN PVD coatings deposited onto plasma nitrited X37CrMoV5-1 type hot work tool steel. Design/methodology/approach: Diffraction and thin film structue were tested with the use of the transmision electron microscopy. The surfaces' thopography and the structure of the PVD coatings were observed on the scanning electron microscopy.The evaluation of the adhesion of coatings to the substrate was made using the scratch test. The wear and friction tests were performed on a pin-on-disc device at the room temperature and at the temperature of 500°C. Findings: The best wear resistance in both conditions (20°C, 500°C temperature) demonstrate the TiN coating. These test results correspond with the very good adhesion of the coating to the substrate material and its high hardness. The critical load L c5 (coating total delamination) lies within the range 86-92 N, depending on the coating type. It was revealed that the coating damage mechanism in the scrtch test commences in all cases with the widespread coating at the edge of the scratch being made and next develops depending on the coating type and location of the originated defects. Practical implications: The good properties of the plasma nitriding and the PVD coatings make them suitable in various engineering and industrial applications. Originality/value: The duplex surfaces treatment of the hot work tool steel for tools made for work at the elevated temperature improves their abrasion wear resistance significantly, compared to coatings developed with the PVD process.
Characteristics of Ti(C,N) and (Ti,Zr)N gradient PVD coatings deposited onto sintered tool materials
Purpose: The purpose of this paper is the characterisation of Ti(C,N) and (Ti,Zr)N thin films produced by cathode arc evaporation physical vapour deposition (CAE-PVD) method onto sintered carbides and sialon tool ceramics. Design/methodology/approach: The GDOS spectrometer was used to indicated chemical concentration changes of the coating components. The phase composition of the investigated coatings was determined by means of the X-ray diffractometer: standard and grazing incidence X-ray diffraction methods. Observations of surface topography and fractures of the deposited coatings were carried out in the scanning electron microscope. Tests of the coatings adhesion to the substrate material were made by use of the scratch test. The microhardness of substrates and coatings were measured by Vickers method. Cutting ability was determined by technological cutting trials. Findings: The studied PVD gradient coatings deposited by cathodic arc evaporation method are demonstrated high hardness, adhesion and wear resistance. The critical load LC2, which is in the range 21-53 N, depends on both the coating type and material substrate. Coatings deposited on sintered carbides are extending tools life. Practical implications: Ti(C,N) and (Ti,Zr)N gradient coatings can be applied for cutting tools. Originality/value: It should be emphasized, that the mechanical properties of the PVD coatings described in this work are very encouraging and therefore their application for products manufacturing at mass scale is possible in all cases where reliable, very hard and abrasion resistant coatings, deposited onto sintered tools substrate are required.
Surface & Coatings Technology, 2018
Cr/CrN/(Cr,N)-DLC/DLC and Cr/Cr-DLC/DLC multilayer coatings have been synthesized using DC sputtering magnetron technique to protect steel substrates from wear. The microstructure was investigated by scanning electron microscopy and the chemical structure of the DLC layers was investigated by Raman spectroscopy. The mechanical and tribological properties were evaluated by nanoindenter, scratch tester and Rockwell 'C' indentation test, ball-on-disk tribometer and surface profiler. A new methodology for the selection of coating performance was proposed by using a performance index based on a mix of adhesion, mechanical and tribological properties.
Recent advances in the chromium nitride PVD process for forming and machining surface protection
Journal of Materials Processing Technology, 2005
This paper reports on the tribological properties of commercial Cr-N physical vapour deposition (PVD) processes for enhanced mechanical protection of forming and machining tools. The study is carried out on conventional tooling materials as substrates, i.e. high speed steels (M2) and cemented tungsten carbide. Electron beam (EB), magnetron sputtering (MS) and cathodic arc (CA) commercial Cr-N PVD processes from three different EU coating centers/companies are evaluated in terms of their tribological behaviour by standard characterization techniques for material properties: surface hardness and roughness, film adherence strength and wear resistance under sliding conditions. The results are discussed on the basis of their current applications and their influence on tool performance for manufacturing processes. Moreover, film tribological performance is correlated with their microstructural properties as obtained by electron microscopy and X-ray diffraction. In terms of surface hardness and adherence strength, CA Cr-N seems to outperform EB and MS coatings. However, EB and MS exhibit enhanced surface finish which might be more appropriate for some applications.
Gradient CrCN cathodic arc PVD coatings
Surface and Coatings Technology, 2008
This work reports on the growth and properties of Cathodic Arc Physical Vapor Deposition of low friction-coefficient CrCN coatings, as deposited on the basis of complementary carbon/nitrogen gradient concentrations through the film thickness. The coatings developed in this study exhibited friction coefficients ranging from 0.2 to 0.6, against 100Cr6 bearing steel, depending on the preparation conditions. Gradient CrCN films with COF of 0.35 and comparable mechanical strength to that of CrN were achieved. The adhesion rate of metallic elements such as Fe during the sliding process of CrCN coated tools on AISI316L steels were monitored using a pin-on-disc experimental set-up. The results demonstrated a low tendency of the gradient CrCN deposited films to pick up material from the AISI316L steels surfaces, in contrast to that found when using standard CrN cathodic arc PVD films.
Chromium carbide coatings obtained by the hybrid PVD methods
Journal of Achievements in …, 2010
Purpose: With the use of the Arc-PVD and Arc-EB PVD hybrid method, the chromium carbide coatings were deposited on steel substrate. Two kinds of coatings were obtained. The nanostructure coatings were formed by deposition of chromium carbide films by Arc PVD evaporation technique. The multilayer coatings were produced by Arc-EB PVD hybrid technology. In the second case the amorphous phase in majority was found in samples, identified by X-ray investigations. Design/methodology/approach: The Arc PVD and combination Arc-EB PVD methods were used for carbide coatings deposition. The special hybrid multisource device, produced in the Institute for Sustainable Technologies-National Research Institute (ITeE-PIB) in Radom, was used for sample deposition. The microstructures of coatings were investigated by JEM 20101 ARP transmission electron microscopy (TEM), TESLA BS500 scanning electron microscopy (SEM) and Olympus GX50 optical microscopy (MO). The X-ray diffraction was utilized to identify phase configuration in coatings Findings: The microstructure of deposited coatings differs depending on the deposition method used. The Arc PVD deposition produced nanometric coatings with the Cr 3 C2, Cr 23 C 6 , Cr 7 C 3 and CrC carbides built from nanometric in size clusters. In the case of the Arc-EB PVD hybrid technology in majority of cases the amorphous microstructure of coatings was found. The hybrid coatings consist of alternating layers of Ni/Cr-Cr 3 C 2. Practical implications: The performed investigations provide information, which could be useful in the industrial practice for the production of wear resistant coatings on different equipments and tools. Originality/value: It was assumed that by using different kinds of PVD methods the different microstructures of coatings could be formed.
Microstructural, mechanical and tribological properties of PA-CVD TiN coatings
A series of tungsten-gradually doped diamond-like carbon (DLC) films with functionally graded interlayer were prepared using a hybrid technique of vacuum cathodic arc/magnetron sputtering/ion beam deposition. With 'compositionally graded coating' concept, the deposition of wear-resistant carbon-based films with excellent adhesion to metallic substrate was realized. In the films, a functionally graded interlayer with layer sequence of Cr/CrN/CrNC/CrC/WC was first deposited onto the substrate, and then, a DLC layer doped with gradually decreasing content of W was coated on. The W concentration gradient along depth of the film was tailored by adjusting the W target current and deposition time. The characterized results indicate that the microstructural, mechanical and tribological properties of these films show a significant dependence on the W concentration gradient. A high fraction of W atom in carbon matrix can promote the formation of sp 2 sites and WC 1 − x nanoparticles. Applying this coating concept, strongly adherent carbon films with critical load exceeding 100 N in scratch test were obtained, and no fractures or delaminations were observed at the end of the scratched trace. The hardness was found to vary from 13.28 to 32.13 GPa with increasing W concentration. These films also presented excellent tribological properties, especially significantly low wear rate under dry sliding condition against Si 3 N 4 ball. The optimum wear performance with friction coefficient of 0.19 and wear rate of 8.36 × 10 −7 mm 3 /Nm was achieved for the tungsten-gradually doped DLC film with a graded W concentration ranging from 52.5% to 17.8%. This compositionally graded coating system might be a potentially promising candidate for wear-resistant carbon-based films in the demanding tribological applications.