Papers by Keyword: TiCN

Abstract: In this study we determined average residual stresses in hard nitride PVD AlCrN, TiAlN and TiCN coatings through simultaneous measurement of length variation in thin-walled tubular substrates and of the curvature of plate substrates. A device for measurement of the length of the tube was developed. Inside the depositing chamber the tube and the plate were fixed parallel in the relation to the axis of the rotating cathode. One batch of plate samples was produced by deposition on front surface (facing the cathode) and the other batch, by deposition on back surface (with back to the cathode). The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM). The thicknesses of the coatings deposited on front and back surfaces of the plates and on the tube were significantly different. The values of average compressive residual stresses, determined by both methods, were very high irrespective of coating thickness. It was found that the values of compressive residual stresses in the coating were dependent on the shape of the substrate and on its position in the relation to the axis of the rotating cathode.

Abstract: This paper is a continuation of our previous work. The article presents an investigation of the influence of coating deposition parameters, in particular a variation with 50% of both cathodic arc current and bias voltage, on the mechanical and tribological properties of TiCN coatings deposited by the cathodic arc evaporation of metals at a constant gas ratio. The thicknesses of the coatings are measured by the Calotest method using a 30-mm hard steel ball. The determined values are in the range of 734 – 1534 nm. Surface morphology and chemical composition are estimated by a Scanning Electron Microscope (SEM) and an Energy Dispersive Spectrometer (EDS) of SEM. The determined values of nanohardness are in the range of 10 - 23 GPa and adhesion values are in the range of 28 - 70 N. Tribology of the TiCN coatings is investigated with three different load forces (3N, 5N and 8N) by the CETR UMI Multi-Specimen Test System from Bruker with an Si3N4 ball counter-body. The friction coefficient is measured in the range of 0.19 - 0.23. Coating wear and wear of the counter-body are calculated, according to the standard EN1071-13:2010, wherein the values of the latter are in the range of (2.5 - 30) x 10-6 mm3.

Abstract: A series of titanium carbonitride (TiCN) films with differing C content were deposited by cathodic arc evaporation of pure Ti in a gas composite environment of N₂ and C₂H₂. The increase of the C₂H₂ fraction in the gas environment leads to a continuous increase in the deposition rate of the TiCN thin films, as well as an increase in the adhesion of the films to the substrate. To evaluate the interaction of the material with the bacteria Escherichia coli CCM 3954 a method was used based on the ČSN EN ISO 56 0100 standard. The bacteria were inoculated in a liquid culture medium. It was observed that the monitored surfaces support the development of bacterial populations of E. coli depending on the type of TiCN thin films.

Abstract: Titanium carbonitride (TiCN) thin films with differing C content were deposited by cathodic arc evaporation of pure Ti in a gas composite environment of N₂ and C₂H₂. Scanning electron microscopy (SEM), scratch test, mechanical profilometer and “ball-on-disc” tribometer methods were used to characterize the surface, the coefficient of friction (CoF) of the TiCN thin films and the evaluated wear. An increase of the C₂H₂ fraction in the gas environment leads to a continuous increase in the deposition rate of the TiCN thin films, as well as an increase in the adhesion of the films to the substrate and the values of the CoF. Tribological test results (when tested against Si₃N₄ balls) show an increase in the friction coefficient of the TiCN from 0.08 to 0.32, with increasing carbon concentration in the film. The CoF decreases rapidly to 0.06 at a C content of 20.6 at.%, N 38.4 at.% and Ti 41.0 at.%.

Abstract: Inconel 718 is a registered trademark of Special Metals Corporation that refers to a family of austenitic nickel-chromium-based super alloys. This material usually being used or operate in high temperature and extreme condition like aerospace industry, turbocharger rotors and seals. This research presents an experimental study of the cutting force variation, surface roughness, tool life and tool wear in end milling Inconel 718. The experimental results showed that flank wear was the predominant failure mode affecting tool life for TiAlN and TiN coated carbide tool. TiAlN is the better coated tool than TiN because it produce better surface finish and resultant force. Feed rate is one of the parameter that effecting results in this experiment. The higher feed rate will shorten the life of the tool. Although for the cutting condition, the situation is quite different where the proper cutting speed will maintain the tool life and tool wear for cutting tool. The overall study shows that TiAlN coated carbide tool with cutting speed 100 m/min, depth of cut 0.5 mm and feed rate 0.1 mm/tooth is the optimum parameter in this experiment.

Abstract: Monolayer titanium carbide nitride (TiCN) and multilayer TiCN reinforced titanium (Ti) are coated on the surface of Ti6Al4V alloy by Filtered Arc Deposition System (FADS). Surface chemical composition has been characterized by an X-ray diffraction (XRD). Wear resistance of TiCN coating and TiCN/Ti coating have been detected by hommel tester T1000. Hardness and deformation mechanisms of the multilayer coatings are investigated using depth-sensing indentation comparison with the monolayer TiCN coatings. Focused Ion Beam (FIB) and Transmission Electron Microscopy (TEM) are used to identify the fracture modes of the coatings. The TEM image observations show that the inclined crack is the dominant crack in the monolayer TiCN coating while small bending crack is the dominant crack in the multilayer TiCN/Ti coating. The Ti layer with good ductility could efficiently suppress the crack propagation and absorb more indent energy.

Abstract: Physical Vapour Deposition and PVD coatings are designed for several applications, from industrial to biomedical. Residual stresses, arising during coating deposition, have important effect on the coating’s service life as their influence to the mechanical and tribological properties. Our aim was to investigate the residual stresses in five different PVD coatings (TiN, TiCN, TiAlN, TiAlN, nc-(AlTi) N/α -Si₃N₄) (presence of the Ti as adhesion layer) by the layer growing curvature method and the X-ray diffraction techniques using a plate and a strip as the substrate. Residual stresses were compressive and very large (2.98 - 7.24) GPa in all coatings and comparable in TiN, TiAlN, TiAlN coatings in the case of both methods. The magnitude of residual stresses is influenced by intrinsic strain in the case of layer growth rather than by thermal stress.

Abstract: A model for designing sandwich nanocomposite ceramic tool materials with symmetrical distribution was presented. By adding nano-sized Al2O3 particles into the submicro-sized Al2O3 and TiCN, Al2O3/TiCN sandwich nanocomposite ceramic tool materials were fabricated by means of powder-laminating and hot-pressing technique. The experimental results showed that optimal mechanical properties were achieved for the composite with the addition of 35 vol.% TiCN particles in the middle layer and 45 vol.% TiCN particles in the outer layers, layer thickness ratio is 0.3, with the flexural strength reaching respectively 900MPa，fracture toughness and Vicker's hardness in the surface layers being 6.5MPa•m1/2 and 19.2GPa.

Abstract: With a newly-developed technique, pulsed high energy density plasma (PHEDP), TiN, TiCN, and (Ti,Al)N coatings were deposited onto silicon nitride and cemented carbide cutting tools. The structures of these coatings were systematically investigated in this paper. The average surface roughness (Ra) of the coated tools were ranged in 20~150 nm. The smooth surface of coated tools means that the coatings are promising candidate for cutting tools of high precision and it is in favor of reducing the fiction coefficients and flank wear of tools. The coating thickness varied, in the range of 3~20 µm, with the deposition conditions of the shot number of pulsed plasma, and the voltages between the inner and outer electrodes of the coaxial gun. The coating has a densified structure compared to the substrate structure and almost no pores and cracks exist in the coating surface. The grain sizes of the coating were small (<100nm), much finer than those of the substrate (>2 µm). Except for TiN-Si3N4 system, no apparent columnar grain structure as presented predominantly in typical vapor deposited coatings was observed. In fact, an equiaxed structure was presented, due to the pulsed mode of plasma bombardment and solid solution strengthening of C or Al into TiN lattices, resulting in disruption, through renucleation, of epitaxy on individual columns. A continuous and densified interface was observed. All these characteristics in structures promised an excellent performance of the coated tools.