Tribological properties of carbonitride coatings formed on titanium by thermodiffusion carbonitriding (original) (raw)
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Analysis of Friction and Wear of Titanium Alloys
2009
Due to the lower-cost processing of titanium, its application in the engines as light weight material has renewed its interest in the tribological behavior. A pin on disk sliding friction test was conducted on the titanium alloy (Ti-6Al-4V). Alloy disks were slid against the bearing ball composed of stainless steels at the speeds of 0.2 and 0.8 m/s. When the sliding speed is higher the coefficient of friction and wear rate are lower. For steel the wear rate is the least. Microstructural study confirms that Ti alloys have the tendency to transfer material to their counter face and there are possible tribological reactions. Degradation of mechanical properties of contact areas of reaction products takes place.
Microstructure and tribological study of TiAlCN and TiTaCN coatings
Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu
The low coefficients of friction and wear rates of transition metal carbonitride make them excellent candidates for friction and wear applications. Coatings based on titanium carbonitride alloyed with Ta and Al were deposited using reactive magnetron sputtering on the surface of titanium VT1-0 and steel AISI 304. The effect of alloying titanium carbonitrides with Ta and Al and acetylene flow during deposition on the structure, composition, and tribological properties of the coating was studied. TiAlCN and TiTаCN coatings were deposited in various acetylene flows along with stable argon and nitrogen flows. Scanning electron microscopy, optical microscopy, X-ray phase analysis, and sliding wear test (ball-on-disk method) in two media were used to study the resulting coatings. The average coefficient of friction of the coating under friction without lubrication varied in the range of 0.13-0.85 and under friction with lubrication in the range of 0.0015-0.081. From the point of view of w...
Wear, 2010
Titanium (Ti) coatings are widely used in biomedical engineering, microelectronics and thin film industry. However, very little is known about its tribological behaviour under dynamic contact conditions. In the light of this, the present work attempts to explore the tribological properties of a micrometer thick Ti coating deposited on a D9 steel substrate. Frictional tests were carried out using a tribometer in linear reciprocating mode against steel, alumina and silicon nitride balls. Three different loads of 1, 3 and 9 N at sliding speeds of 0.1, 0.5 and 2 cm/s were used to induce different contact conditions. Wear was calculated in terms of wear rate. Resulted tribo tracks were analysed using optical microscopy, scanning electron microscopy and Raman spectroscopy. Distinct deformation behaviours were observed which led to the formation of different kind of wear debris as revealed by SEM observations. The coefficient of friction was found to decrease with increase in speed but opposite trend was observed with increase in load with all the mating partners used. Wear rates were found to increase with corresponding increase in load and speed. Highest wear rates were observed in case of alumina ball and lowest were observed in case of silicon nitride ball. These observations have significant bearing while using Ti coating for wear resistant applications.
Wear, 2019
Though TiN coatings are considered a reliable anti-wear solution, the recent studies show that the anti-wear capacity of the TiN-coated metallic materials can be limited by various factors. Therefore, in our study, the CAE-PVD TiN film was deposited on two popular metallic materials: 316LVM stainless steel and Ti6Al4V alloy. The surface roughness, mechanical properties, adhesion as well as anti-wear performance in tribological pair with Ø6 mm WC-Co ball of both bare and surface modified specimens were evaluated. According to the findings, the elastic modulus mismatch between the coating and the substrate is one of the key factors that determine the operational durability of the TiN-coated alloys. Moreover, the well-established H/E and H 3 /E 2 quotients should be treated with caution when the wear performance of a coated material is assessed.
Wear, 2015
TiN and TiCN coatings have long been used for wear reduction in application like tooling, but there are other potential industrial applications in aqueous environments. Therefore, the current investigation explores the friction and wear compatibility of TiN and TiCN coatings against potential sliding partners in water. 316 L discs coated with TiN and TiCN (containing 2.46 at% C) slid against fixed balls of Al 2 O 3 , SiC, Si 3 N 4 , and SUS440C in water. In terms of mean steady-state friction coefficient, the ranking from low to high was: SiCoSi 3 N 4 oAl 2 O 3 oSUS440C regardless of coating type. It is proposed that due to lubrication by silica gel, the friction coefficients and wear rates of TiCN coatings against SiC and Si 3 N 4 balls were lower than those against Al 2 O 3 and SUS440C balls. For the TiCN/SUS440C tribopairs, tribo-oxidation occurred easily for SUS440C ball, and the oxides on the wear track caused the highest friction coefficient and the roughest wear surfaces. But wear of the TiCN/Al 2 O 3 tribopairs, which had the highest wear rate of the coatings, was dominated by abrasion. In terms of the friction and wear behavior under water-lubricated test conditions, SiC was the most suitable counterpart for TiCN-coated stainless steel.
Tribological characteristics of titanium nitride and titanium carbonitride multilayer films
Thin Solid Films, 2001
In this study, the specimens in disc style were prepared by changing the coating sequence and coating thickness of titanium nitride and titanium carbonitride films on S45C steel substrate as the top and the second layers of a multilayer system. These arrangements were made in order to investigate the mechanical properties of the composite films like the adhesion strength, load carrying capacity, hardness, surface topography and surface microstructure. The experimental results show that the specimens Ž. Ž. with the TirTi C,N rTiN film have a relatively higher composite hardness than the TirTiNrTi C,N film. The trend exhibited in Ž. the coating film hardness of ceramic coating film is similar to the composite hardness. The specimens with the TirTi C,N rTiN Ž. film have a lower critical friction force and critical track distance compared with the TirTiNrTi C,N film. For the specimen with Ž. the TirTi C,N rTiN film, peaks protruding over the flat surface are quantitatively increased by the increase in the coating film thickness. Nevertheless, either the peak parameter Rz or the amplitude parameter Ry after coating thick films is strongly affected by the Ra value of steel substrate before coating and the uniformity of the surface morphology can thus be improved. However, Ž. for the specimens with the TirTiNrTi C,N film, increasing the total film thickness decreased the asperity, but also eliminated the morphological uniformity.
Materials Science and Engineering: A, 1991
The results of tests on new multielement ceramic coatings based on (Ti,AI)N and Ti(B,N) deposited by plasma-assisted physical vapour deposition are reported. The work follows on from earlier studies based on standardized test procedures and now includes model cutting tests. The paper emphasizes the markedly different.tribological behaviour of these coatings depending on the contact conditions-even on different faces of the same tool. The need to further develop such coatings for specific contact conditions is therefore highlighted.
Wear, 2006
Thermal degradation of environmentally friendly lubricants prevents the spread of its utilisation in industrial applications. This process can be promoted by frictional heating occurred during accidental contacts of moving parts or star-up and shutdown operations. The use of low friction coatings, like diamond-like carbon (DLC), can offer a solution to these problems. Their low friction properties, high wear resistance and excellent corrosion resistance can prevent the occurrence of such local heat spikes, which will protect the lubricant and hence prolong the lifetime of the tribological system. In this work, a synthetic bio-lubricant has been evaluated and compared with a mineral oil. Combinations with pure and Ti doped DLC coatings were taken into account. In order to have a proper evaluation of the tribosystem a wide range of conditions have been considered in high frequency reciprocating and unidirectional tests. The Stribeck curve at variable sliding speeds and loads was obtained. In steel/steel contacts friction is clearly lower when synthetic oil is used compared to a mineral based oil, which is not always true with DLC/DLC contacts. As a result of the tribotesting, the best combination of materials was chosen in order to be validated in a real system (mechanical component in a machine tool), where results confirmed our expectations.
2021
Titanium forming processes are often limited by severe adhesive wear as a result of poor friction conditions. This can be partially remedied with careful selection of lubricant, billet preparation and tool coating, but the optimal combination of these factors is not known. A full factorial ring compression experiment, with grade 2 commercially pure titanium rings deformed at 300 °C, was conducted to study the effect of each of these factors over three levels. The change in internal diameter was compared to a set of calibration curves generated by an FEA simulation of the process in order to determine the friction coefficient during each trial. A robust statistical analysis methodology was used to isolate and evaluate the effect of varying each factor. The choice of lubricant was found to be the most statistically significant factor by a considerable margin, followed by the method of billet preparation, with tool coating found to be insignificant. Of the lubricants tested, the graphi...
Investigation of Thermodiffusion Carbonitride Coatings on Titanium Alloys
Materials Science, 2005
We study specific features of the processes of phase formation and gas saturation in VT1-0, VT14, OT-4, and VT20 titanium alloys held in a carbon-and-nitrogen-containing medium for 5 h at 1100°C. Depending on the type of alloy, the TiC x N y carbonitride phases of different compositions are formed on the metal surface under the indicated conditions. The analysis of the corrosion and electrochemical behavior of alloys shows that the best protective properties are exhibited by the carbonitrides formed on the surface of VT20 alloy (whose composition is close to equiatomic and the surface roughness is minimum). Titanium monocarbides and mononitrides have similar crystal structures and the same type of chemical bonds. Therefore, one may observe the formation of pseudobinary equilibrium of TiC + TiN with their complete mutual dissolution and formation of TiC x N y titanium carbonitrides, i.e., ternary compounds of variable composition with broad regions of homogeneity [1, 2]. The properties of carbonitrides are, for the most part, inherited from binary compounds (carbide and nitride). However, some of these properties are better than the corresponding properties of the binary phases [3, 4]. This is connected with nonlinear changes in the parameters of the electron structure of the ternary compound and chemical bonding between the atoms of the crystal lattice depending on its composition [5]. This is why these compounds are of significant interest for the researchers. In what follows, we focus our attention on the corrosion characteristics of carbonitride coatings on titanium alloys. Procedure We study polished specimens (15 × 10 × 1 mm) made of the following commercial titanium alloys: VT1-0 commercially pure titanium (α-alloy), OT4 and VT20 pseudo-α-alloys of the Ti-Al-Mn and Ti-Al-Mo-V-Zr systems, respectively, and VT14 (α + β)-alloy of the Ti-Al-Mo-V system. The specimens were carbonitrided by thermodiffusion saturation in commercially pure nitrogen under an atmospheric pressure at 1100°C with isothermal holding for 5 h. Prior to the delivery into the reaction space of the furnace, nitrogen was separated from oxygen and moisture (≤ 0.05%) by passing through a capsule with silica gel and titanium chips heated to a temperature higher than the temperature of saturation by ∼ 50°C. The specimens were placed in a charge of MG powder-electrode graphite. The electrochemical behavior of carbonitride coatings was studied in 40% and 80% aqueous solutions of sulfuric acid at a temperature of 18°C under the conditions of free access of oxygen. The polarization curves were recorded in a PI-50-1.1 potentiostat at a potential-sweep speed of 0.1 V / sec. The potentials were presented relative to the silver-chlorine electrode. The specimens were covered with an acidproof polymer but their work