Tribological performance of hybrid filtered arc-magnetron coatings. Part II: Tribological properties characterization (original) (raw)
Related papers
Tribological performance of hybrid filtered arc-magnetron coatings
Surface & Coatings Technology, 2006
Aircraft propulsion applications require low-friction and wear resistant surfaces that operate under high contact loads in severe environments. Recent research on supertough and low friction nanocomposite coatings produced with hybrid plasma deposition processes was demonstrated to have a high potential for such demanding applications. However, industrially scalable hybrid plasma technologies are needed for their commercial realization. The Large area Filtered Arc Deposition (LAFAD) process provides atomically smooth coatings at high deposition rates over large surface areas. The LAFAD technology allows functionally graded, multilayer, super-lattice and nanocomposite architectures of multi-elemental coatings via electro-magnetic mixing of two plasma flows composed of different metal ion vapors. Further advancement can be realized through a combinatorial process using a hybrid filtered arc-magnetron deposition system. In the present study, multilayer and nanostructured TiCrCN/TiCr + TiBC composite cermet coatings were deposited by the hybrid filtered arc-magnetron process. Filtered plasma streams from arc evaporated Ti and Cr targets, and two unbalanced magnetron sputtered B 4 C targets, were directed to the substrates in the presence of reactive gases. A multiphase nanocomposite coating architecture was designed to provide the optimal combination of corrosion and wear resistance of advanced steels (Pyrowear 675) used in aerospace bearing and gear applications. Coatings were characterized using SEM/EDS, XPS and RBS for morphology and chemistry, XRD and TEM for structural analyses, wafer curvature and nanoindentation for stress and mechanical properties, and Rockwell and scratch indentions for adhesion. Coating properties were evaluated for a variety of coating architectures. Thermodynamic modeling was used for estimation of phase composition of the top TiBC coating segment. Correlations between coating chemistry, structure and mechanical properties are discussed.
2008
The demand for low-friction, wear and corrosion resistant components, which operate under severe conditions, has directed attention to advanced surface engineering technologies. The large area filtered arc deposition (LAFAD) process has demonstrated atomically smooth coatings at high deposition rates over large surface areas. In addition to the inherent advantages of conventional filtered arc technology (superhardness, improved adhesion, low defect density), the LAFAD technology allows functionally graded, multilayer, and nanocomposite architectures of multi-elemental coatings via electro-magnetic mixing of two plasma flows composed of different metal vapor ion compositions. Further advancement is realized through a combinatorial process using a hybrid filtered arc-magnetron technique to deposit multilayer nanocomposite TiCrN + TiBC cermet coatings. Multiple TiCrN + TiBC coating architectures were reviewed for their ability to provide wear resistance for Pyrowear 675 and M50 steels used in aerospace bearing and gear applications. Coating properties were characterized by a variety of methods including SEM/EDS, HRTEM, and XRD. Wear results were obtained for high contact stress boundary lubricated sliding and advanced bearing simulation testing for wear performance under oil-off operating conditions. The best coating candidates demonstrated order of magnitude increases in resistance to sliding wear, and extended low friction operation during simulated oil-off events. Coating failure mechanisms were brittle in nature and suggestions are presented for the further optimization of TiCrN + TiBC coating architectures.
2014
The demand for economical high-performance materials has brought attention to the development of advanced coatings. Recent advances in high power magnetron sputtering (HPPMS) have shown to improve tribological properties of coatings. These coatings offer increased wear and oxidation resistance, which may facilitate the use of more economical materials in harsh applications. This study demonstrates the use of novel forms of HPPMS, namely modulated pulsed-power magnetron sputtering (MPPMS) and deep oscillation magnetron sputtering (DOMS), for depositing TiN and Ti 1-x Al x N tribological coatings on commonly used alloys, such as Ti-6Al-4V and Inconel 718. Both technologies have been shown to offer unique plasma characteristics in the physical vapor deposition (PVD) process. High power pulses lead to a high degree of ionization compared to traditional directcurrent magnetron sputtering (DCMS) and pulsed magnetron sputtering (PMS). Such a high degree of ionization was previously only achievable by cathodic arc deposition (CAD); however, CAD can lead to increased macroparticles that are unfavorable in high friction and corrosive environments. MPPMS, DOMS, and other HPPMS techniques offer unique plasma characteristics and have been shown to produce coatings with refined grain structure, improved density, hardness, adhesion, and wear resistance. Using DOMS and MPPMS, TiN and Ti 1-x Al x N coatings were deposited using PMS to compare microstructures and tribological performance. For Ti 1-x Al x N, two sputtering target compositions, 50Ti-50Al and 30Ti-70Al, were used to evaluate the effects of MPPMS on the coating"s composition and tribological properties. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to characterize microstructure and crystallographic texture. Several tribological properties were evaluated including: wear rate, coefficient of friction, adhesion, and nanohardness. Results show that substrate material can have a significant effect on adhesion and the mechanical response between the coating and substrate. Depending on deposition parameters and the selected material MPPMS and DOMS are promising alternatives to DCMS, PMS, and CAD.
Journal of Adhesion Science and Technology, 2015
The properties of TiBN-based coatings are significantly affected by adding alloying elements and coating parameters. Therefore, in this study, TiTaBN coatings with graded interlayer (CWGIL) were deposited on D2 steel substrates by pulsed DC biased (PDCB) and continuously DC biased (CDCB) closed field unbalanced magnetron sputtering (CFUBMS). The structural, mechanical, adhesion and tribological properties of the coatings were analysed with EDS, SEM, XRD, microhardness, scratch testing and a pin-on-disc tribo-tester (under various atmospheric conditions). TiTaBN CWGIL deposited by PDCB magnetron sputtering (MS) had a very dense microstructure, high hardness and a high critical load value. TiTaBN CWGIL deposited by PDCB MS had a lower friction coefficient, the wear rate and the penetration depth in all atmospheric conditions. In conclusion, the application of a PDCB substrate instead of a CDCB one dramatically increases the performance of CFUBMS-deposited TiTaBN coatings.
Tribological behavior of TiC/TaC-reinforced cermet plasma sprayed coatings tested against sapphire
Wear, 1995
This paper deals with the investigation of the tribological behavior of TiC/TaC reinforced NiCrMo and MO plasma sprayed coatings. The coatings were classified with respect to friction and wear behavior in pin-on-disk tests. The NiCrMo-based coatings, with better carbide-metal matrix binding than the MO-based coatings, are also the more wear resistant. The NiCrMo-based coatings show a better functionality, when the reinforcing particles are a solid solution of TIC and TaC, than the coatings with only TiC or TaC reinforcement. Abrasion, adhesion and fracture assisted wear were observed to be the primary wear mechanisms involved in these complex TiC/TaC reinforced coatings, as revealed by SEM investigation of the wear tracks and the debris. The extent of each mechanism appears to be influenced by the carbide-matrix interface strength. The processing to structure and functionality relationships highlight the key parameters in the effort to design high wear resistant coatings.
The structure and mechanical and tribological properties of TiBCN nanocomposite coatings
Acta Materialia, 2010
TiBCN nanocomposite coatings were deposited in a closed field unbalanced magnetron sputtering system using pulsed magnetron sputtering of a TiBC compound target with various Ar/N 2 mixtures. TiBCN coatings were characterized using X-ray diffraction, Xray photoelectron spectroscopy, transmission electron microscopy, nanoindentation, Rockwell C indentation and ball-on-disk wear tests. The coatings with a nitrogen content of less than 8 at.% exhibited superhardness values in the range of 44-49 GPa, but also showed poor adhesion and low wear resistance. Improvements in the coating adhesion, H/E ratio and wear resistance were achieved together with a decrease in the coating hardness to 35-45 GPa as the N content in the coatings was increased from 8 to 15 at.%. The microstructure of the coatings changed from a nano-columnar to a nanocomposite structure in which 5-8 nm nanocrystalline Ti(B,C) and Ti(N,C) compounds were embedded in an amorphous matrix consisting of BN, free carbon and CN phases. With a further increase in the N content in the coatings to levels greater than 20 at.%, the inter-particle spacing of the nanocrystalline compounds increased significantly due to the formation of a large amount of the amorphous BN phase, which also led to low hardness and poor wear resistance of the TiBCN coatings.
Structure and Properties of Hybrid Coatings
This review report presents both the results obtained by the authors and those of other authors concerning investigations of structure and properties of hybrid coatings. Examples of such coatings as Al2O3/Cr/TiN/steel, NiCr/steel; CrNiBSi/steel and others before and after electron beam irradiation had been considered. In these coatings the thickest layer was deposited using the high velocity pulsed plasma jet, all others being deposited in vacuum by the vacuum arc source or implanter. Advantages of the high velocity pulsed plasma jet in comparison with other technologies had been demonstrated. A wide spectrum of ana- lyzing methods had been applied for analyses: TEM, SEM with EDS, RBS, NRA, SIMS, XRD, tests for corrosion, wear, adhesion and hardness.
The processing and testing of new and advanced materials for wear resistant surface coatings
Journal of Materials Processing Technology, 1997
In the search of wear resistant coatings for applications such as cutting tools and turbine refurbishing, we have produced and tested a wide range of coatings including nanocrystalline metals (At, Ti, Cu), nanolaminated composites, containing alternating layers of metal-ceramic (AI 2 0] and TiffiN) or metal-metal (Ti/Cu), and monolithic coatings (TiN). These coatings were produced using an r.f. magnetron sputtering system except for the monolithic TiN which was commercially produced using an ion plating system. All these coatings were tested for their tribological (friction and wear) and mechanical (hardness) properties using a pin-on-disc type wear rig and an ultra-microindentation system, respectively. The tribological properties that were used to compare the relative performance of these materials were the coefficients offriction (both peak and steady-state) and the wear rates (volume loss pef unit sliding distance) in both the severe and mild wear regimes. The optimum combination of a low coefficient of friction and low wear rate in the steady-state regime was exhibited by TiffiN nanolaminated composite coating with a 150 nm Ti layer thickness and a 20 nm TiN layer thickness. This material also exhibited the highest hardness ofthe composite coatings. The micromechanisms responsible for the differences in hardness and wear resistance of these materials are discussed and recommendations are made on future directions for producing improved wear resistant coatings.