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The Tactical Information Communication Network(TICN) is a crucial element in determining the success of military operations. Particularly, the construction of an efficient network through the shortest possible connections is essential for rapid and stable communication. This paper presents a mathematical model for the optimal deployment of Node Communication Stations within TICN, applying Mixed Integer Programming(MIP) with Minimum Spanning Tree (MST) and Steiner Tree algorithms. The model aims to configure Communication Stations into a single network for effective data distribution. Simulation results indicate that the model can minimize connection distances and the number of Node Communication Stations required, thereby forming a single cohesive network of Unit Communication Stations. This approach is expected to support decision-making for efficient communication network construction, especially under limited resources and time constraints during military operations. The proposed mathematical model plays a crucial role in enhancing the stability and maximizing the efficiency of communication networks in military operations. [ABSTRACT FROM AUTHOR]

In this paper, we describe the mechanical characteristics of Al2O3 and TiCN thin films formed by chemical vapor deposition (CVD) and a TiAlN thin film formed by physical vapor deposition (PVD), which are used as hard coating films. A focused ion beam (FIB) was used to fabricate a microcantilever beam for strength tests and fracture toughness tests under bending. A nanoindentation system was used to apply normal force to cantilever beams. All the films showed a linear force–deflection relationship, indicating brittle fracture during elastic deformation. The Young’s modulus ranged from 340 to 379 GPa, with no significant difference among the films, whereas the fracture strength of the Al2O3 films was 5.5 GPa, which was almost twice those of the other two films. For the fracture toughness test, a precrack with various depths was made using FIB at 2 μm from the fixed end of the cantilever beam. The Al2O3 film toughness values ranged from 4.1 to 5.5 MPa√m, which were almost twice that of the TiCN film at each precrack depth. Both CVD films showed a similar trend, i.e., an increase in fracture toughness with decreasing precrack depth, However, the fracture toughness of the TiAlN film showed no precrack depth dependence. The difference in fracture toughness between the CVD and PVD films is discussed on the basis of fracture surface observation results and information on the crystal grain size and orientation. [ABSTRACT FROM AUTHOR]

This study aims to characterise TiCN coatings deposited on Ti6Al4V by physical vapour deposition. Findings on surface morphology, geometric structure, adhesion, instrumental hardness, and tribology are presented. Microscopic examination revealed a uniform coating with a thickness of about 1.5 µm and roughness (Sq) equal to 0.13 µm. Mechanical tests showed that the coating deposition increased the hardness of the Ti6Al4V alloy by about 75%. The artificial saliva solution used in the tribological tests reduced the coefficient of friction and the volumetric wear of the tested friction pairs. Microscopic observations of wear tracks after tribological tests allowed for the identification of wear mechanisms: micro-cutting/ploughing wear dominated in both the Ti6Al4V alloy and TiCN coating samples, but wear was much less pronounced overall with the TiCN coating. The study results demonstrate that the deposition of a TiCN coating simultaneously imparts low-friction and anti-wear properties to the surface of titanium alloys. [ABSTRACT FROM AUTHOR]

This paper examines the impact of a multilayered gradient coating, applied via plasma-activated chemical vapor deposition (PACVD), on the structural and mechanical attributes of nanostructured WC-Co cemented carbides. WC-Co samples containing 5 and 15 wt.% Co were synthesized through a hot isostatic pressing (HIP) process using nanoparticle powders and coated with two distinct multilayer coatings: titanium nitride (TiN) and titanium carbonitride (TiCN). Nanosized grain formation without microstructural defects of the substrates, prior to coating, was confirmed by magnetic saturation and coercivity testing, microstructural analysis, and field emission scanning electron microscope (FESEM). Nanoindentation, fracture toughness and hardness testing were conducted for uncoated samples. After coatings deposition, characterizations including microscopy, surface roughness determination, adhesion testing, coating thickness measurement, and microhardness examination were conducted. The impact of deposited coatings on wear resistance of produced hardmetals was analyzed via scratch test and dry sliding wear test. Samples with higher Co content exhibited improved adhesion, facilitating surface cleaning and activation before coating. TiN and TiCN coatings demonstrated similar roughness on substrates of identical composition, suggesting Co content's minimal influence on layer growth. Results of the mechanical tests showed higher microhardness, higher elastic modulus, better adhesion, and overall superior tribological properties of the TiCN coating. [ABSTRACT FROM AUTHOR]

Albeit nanozymes‐based tumor catalytic therapy (NCT) relies on endogenous chemical reactions that could achieve tumor microenvironment (TME)‐specialized reactive oxygen species (ROS) production, the unsatisfactory catalytic activity of nanozymes accompanied by complex TME poses a barrier to the therapeutic effect of NCT. Herein, a one‐step in situ synthesis strategy is reported to construct ternary Ru/TiO2−x@TiCN heterojunctions through oxidative conversion of TiCN nanosheets (NSs) to TiO2−x NSs and reductive deposition of Ru3+ to Ru nanoparticles. The narrow bandgap and existence of heterojunctions enhance the ultrasound‐activated ROS generation of Ru/TiO2−x@TiCN because of the accelerated electron transfer and inhibits electron–hole pair recombination. The augmented ROS production efficiency is achieved by Ru/TiO2−x@TiCN with triple enzyme‐like activities, which amplifies the ROS levels in a cascade manner through the catalytic decomposition of endogenous H2O2 to relieve hypoxia and heterojunction‐mediated NCT, as well as depletion of overexpressed glutathione. The satisfactory therapeutic effects of Ru/TiO2−x@TiCN heterojunctions are achieved through synergetic sonodynamic therapy and NCT, which achieve the complete elimination of tumors without recurrence. This strategy highlights the potential of in situ synthesis of semiconductor heterojunctions as enhanced sonosensitizers and nanozymes for efficient tumor therapy. [ABSTRACT FROM AUTHOR]

Additive Manufacturing is experiencing an upswing in many sectors of industry for a broad variety of materials. Processes are mainly developed for polymers and metals. For ceramics, hardmetals and especially cermets there are only a few additive processes suitable. The powder-based technique Binder-Jetting is one of these suitable processes with high productivity and relatively low green density. Within this study, TiCN-based cermets are printed by Binder-Jetting for the first time. The complexity of influences of the morphology and composition of cermet powders are discussed in regard to bulk density and material properties of printed and sintered parts. Studied TiCN-based cermet compositions represent different Ni and Mo2C contents. Main points of this investigation are further the adjustment of ratio of the raw materials for good sintering behaviour and their influence on the microstructures and as a function of varied sintering temperatures. [ABSTRACT FROM AUTHOR]

TiCN coatings are applied to tool steels surfaces to increase tool life because of attractive properties such as high hardness and toughness. The addition of different alloy elements to the structure of TiCN leads to significant improvements in their mechanical and tribological properties. In this study, to increase the life of AISI H13 tool steel, TiCN and Ta-doped TiCN coatings were deposited by Closed Field Unbalanced Magnetron Sputtering system and the effects of Ta on the structural, mechanical and tribological properties of TiCN coatings were investigated. The effect of the Ta target current has been studied by varying its value from 0 to 3 and to 6A. Structural properties were determined by SEM, XRD and XPS. Mechanical properties were obtained by nanoindentation and adhesion tests. A pin-on-disk tribotest device was used to determine the tribological properties (friction coefficient and wear rate). With the addition of Ta to TiCN, an increase in the thickness of the coatings and a decrease in grain size were observed. The amount of C-C (sp3) increased in TiCN coatings with increasing Ta target current. Increased sp3 amount increased the hardness of the coatings. The results show that the increasing amount of Ta improves the mechanical and tribological properties of TiCN coatings. In addition, TiCN and Ta-TiCN coatings significantly improved the mechanical and tribological properties of substrate. [ABSTRACT FROM AUTHOR]

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This work evaluated the influence of titanium carbo-nitride (TiCN), chromium aluminum nitride (CrAlN), and boron carbo-nitride (BCN) coatings deposited on AISI 1045 steel and their behavior in fatigue life. Suitable deposition parameters were established to obtain appropriate deposition times for polycrystalline growth and desired stoichiometry, as well as a stable layer thickness of ~ 3 μm. The physical and chemical properties of the obtained coatings were established by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nanoindentation. Scanning electron microscopy (SEM) was used for analyzing the fracture surfaces of the samples subjected to fatigue. The analysis of the fatigue behavior of the uncoated and coated substrates was performed under rotary bending conditions applying maximum alternating stresses in the interval of 55 to 70% of the ultimate strength value, i.e., from 479 to 610 MPa, respectively. The test was conducted at room temperature. It was established that the fatigue resistance properties increased for the three types of coated samples, TiCN, BCN, and CrAlN, with values of 9.6%, 4.2%, and 3.9%, respectively, calculated for 1 × 106 cycles. The highest value in fatigue life improvement corresponded to the TiCN coating. This is associated with the increase in the mechanical properties of the coating, as well as the lower presence of tensile type stresses. The mechanical and fatigue results found in these ternary coatings deposited on AISI 1045 steel open up the possibility of future applications in mechanical devices, e.g., automotive applications with high fatigue demands in service conditions. [ABSTRACT FROM AUTHOR]

In this work, different plasma nitriding and coating thickness combinations were tested to improve surface proprieties of a cold work tool steel. A DIN X100CrMoV8-1-1 cold work tool steel was plasma nitrided, using a 5 vol-%. N2 + 95 vol-% H2 gas mixture, for 2.5- and 5.0-h nitriding times. Then, the non-nitrided and nitrided substrates were coated with titanium carbonitride (TiCN)-graded thin films produced by cathodic arc plasma-assisted physical vapor deposition. Different deposition parameters were used to produce coatings with thicknesses of 1.0 and 2.0 µm. The samples were characterized regarding the microstructure, surface hardness, coating adhesion, and friction coefficient, which were measured by ball-on-disc tests. In the plasma nitriding process, it was possible to generate a diffusion layer, without the formation of a compound layer, with depths of 58 µm and 68 µm for 2.5 and 5.0 h, respectively. Both plasma nitriding treatments avoided delamination of the TiCN coating when deposited on the cold work tool steel. The TiCN coatings significantly decreased the friction coefficient, regardless of substrate condition. The lowest friction values were found for the thinner coating. The deeper diffusion zone led to higher hardness value, and highest scratch crack propagation resistance of the coatings, meaning superior coating adhesion. The best surface properties were found when combining the deeper plasma nitriding diffusion layer with the thinner PVD coating. [ABSTRACT FROM AUTHOR]

The structural and electrochemical properties of the AISI 1045 steel coated with the following coatings, deposited using physical vapor deposition (PVD), were determined: titanium carbo-nitride (TiCN), chromium aluminum nitride (CrAlN) and boron carbo-nitride (BCN). A comparison of the x-ray diffraction results with the XPS results revealed that Ti-C-N, B-C-N and Cr-Al-N were the dominant constituents. The selected deposition conditions such as the nitrogen and carbon contents and activation energy were sufficient to form the coatings. The EIS results showed that CrAlN had the lowest porosity content, followed by TiCN and BCN. These data are linked to the polarization resistance of TiCN, CrAlN and BCN: Rp = 126.42x1010 ± 8.939x1011 KΩ cm2, Rp = 40.49x1010 ± 2.863x1011 KΩ cm2 and Rp = 23.10x1010 ± 1.633x1011 KΩ cm2, respectively; as well as the corrosion rate: 0.0049 ± 0.019 mm for CrAlN, 0.0123 ± 0.014 mm for TiCN and 0.0174 ± 0.010 mm for BCN. The AISI 1045 steel with the CrAlN coating had a higher corrosion resistance compared to the other coatings because Cr increased the electronegativity of CrAlN. These results indicate that the structural and electrochemical properties of the materials, the latter carried out in lubricated environments with simulated real service conditions, depend largely on the nature of the coating. Furthermore, these analyzed coatings can be used on components subjected to stresses with high wear in lubricated environments, specifically in the automotive and metalworking industries. [ABSTRACT FROM AUTHOR]

In this present research, the machinability studies of TiAlN/TiCN, TiCN/TiAlN coated and uncoated inserts were investigated on machining custom 450 alloy. The machining input parameters such as feed rate (f), cutting speed (V) and depth of cut (d) are set using orthogonal array. The machining output parameters such as surface roughness, tool wear and cutting forces were studied for its parametric contribution and it was analyzed using Analysis of Variance (ANOVA). Further, the tool wear obtained was studied using scanning electron microscopic images and energy dispersive spectroscopy analysis was conducted to check the addition of work material elements to the coated tool surface. The results show that, the feed rate is the most contributing factor in deciding resultant forces, surface roughness and tool wear respectively. TiAlN/TiCN coated carbide tool has obtained improved machinability, when compared to TiCN/TiAlN coated carbide and uncoated carbide inserts. To obtain one optimal level for all three responses of three types of tools, multi criteria decision making approach, named utility concept approach is selected. Based on the MCDM analysis, it is found that trial number 4 gives better experimental output of improved surface integrity, lower resultant force and less tool wear for all types of tools. [ABSTRACT FROM AUTHOR]

Multi-spindle drilling simultaneously produces multiple holes to save time and increase productivity. The assessment of hole quality is important in any drilling process and is influenced by characteristics of the cutting tool, drilling parameters and machine capacity. This study investigates the drilling performance of uncoated carbide, and coated carbide (TiN and TiCN) drills when machining Al2024 aluminium alloy. Thrust force and characteristics of hole quality, such as the presence of burrs and surface roughness, were evaluated. The results show that the uncoated carbide drills performed better than the TiN and TiCN coated tools at low spindle speeds, while TiCN coated drills produced better hole quality at higher spindle speeds. The TiN coated drills gave the highest thrust force and poorest hole quality when compared with the uncoated carbide and TiCN coated carbide drills. Additionally, a multi-layer perceptron neural network model was developed, which could be useful for industries and manufacturing engineers for predicting the surface roughness in multi-hole simultaneous drilling processes. [ABSTRACT FROM AUTHOR]

The effect of nanosized composition (NC) based on TiN, SiC and TiCN nanopowders on the corrosion behavior of nanomodified AlSi7Mg alloy is investigated. Accelerated corrosion tests are carried out to compare the resistance of the non-modified and nanomodified AlSi7Mg alloys to uniform, intergranular and pitting corrosion. The uniform corrosion (UC) test is performed by the gravimetric method through continuous immersion of the specimens in a 3 % NaCl + 0.1 % H2O2 solution for 360 h at 25°C and 50°C. The intergranular (IGC) and pitting corrosion (PC) tests are performed in a 3 % NaCl + 1 % HCl at 25°C under complete immersion conditions. Data on the change of the modified alloys corrosion rate depending on the solutions temperatures and the modifiers type is obtained. It is found that UC occurs in all investigated alloys 3,1 to 5,7 times faster at 25°C than at 50°C. No clear dependence of the penetration depth of IGC as well as of the corrosion pits density and size on the type of NC is observed. The type, the composition and the crystallinity degree of the corrosion products deposited on the specimens' surface at both temperatures are investigated by X-ray diffraction analysis. The crystallinity degree of the modified alloys is higher compared to that of the non-modified alloy depending on both the modifier composition type and the solutions temperature. [ABSTRACT FROM AUTHOR]

The low adherence of diamond-like carbon (DLC) films on titanium (Ti) alloys can be improved by using interlayer coatings. In this study, DLC (a-C:H) films were deposited using radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD), and a TiCN interlayer was applied between the extra low interstitial (ELI) grade of Ti-6Al-4V alloy and a-C:H film. The characteristics of the a-C:H-coated Ti-6Al-4V ELI alloy were investigated using field emission scanning electron microscopy, Vickers hardness, and scratch and wear tests. The DLC (a-C:H) films deposited by rf-PECVD had a thickness of 1.7 µm, and the TiCN interlayer had a thickness of 1.1 µm. Vickers hardness of the DLC (a-C:H) films were increased as a result of the influence of the TiCN interlayer. The resulting friction coefficient of the a-C:H-coated Ti-6Al-4V with the TiCN interlayer had an extremely low value of 0.07. [ABSTRACT FROM AUTHOR]

In this study, the microstructural and densification behavior of titanium nitride (TiN) and titanium carbonitride (TiCN) reinforced Ti-6Al-4V were investigated under an applied pressure of 50 MPa, sintering temperatures of 1000–1100 °C, heating rate of 100 °C/min and dwell time of 10–20 min through spark plasma sintering technique. Results show that the microstructural transformation of the titanium matrix composite comprises of a mixture of lamellar colonies with β grain boundaries and nanoparticles with an average grain size range of 4.5–6.0 μm. Furthermore, an addition of nanoceramics TiN/TiCN resulted in microstructural transformation, uniform particle distribution within the metal matrix and along the grain boundary. However, the sintered relative density of the composites decreased with the percentage increase in TiCN, while fully dense composites were obtained at a sintering temperature of 1100 °C. Microhardness values of the sintered composites reach a greater level in comparison to Ti-6Al-4V alloy while fracture morphology of the sintered composites with addition of nanoceramics (TiN/TiCN) displayed a transgranular transformation within the matrix accompanied with fine dimple features. [ABSTRACT FROM AUTHOR]

The nanomodification of cast iron is usually performed in order to improve its mechanical properties but it influences also its microstructure and corrosion properties. The impact of nanomodification is studied on cast iron GG25 modified by introducing a nanocomposition melt of 5TiCN:3Y2O3:16Cr:5Fe. The metallographic observations of the modified and the non-modified cast samples show significant refinement of the carbide lamellae, the pearlite areas and the phosphide eutectic in the modified sample. The method of accelerated corrosion testing by cyclic immersion in two types of model corrosion environments is applied in order to estimate the modified and unmodified samples corrosion behavior. Data on the corrosion rate changes during the test and after it (1240 h) in groundwater and 3% aqueous solution of NaCl is obtained. A decrease of the corrosion rate of the modified cast iron compared to that of the non-modified one is registered after the end of the test in both corrosion environments: a decrease of 33% in groundwater and of 6% in 3% NaCl solution. The type, the composition and the crystallinity degree of the corrosion products deposited on the samples surface in both environments are investigated by X-ray diffraction analysis. The established decrease of crystallinity after modification is related to the general refinement of the microstructure. [ABSTRACT FROM AUTHOR]

Two different steel substrates were coated with the same gradient multilayer TiN/TiCN coating in the plasma‐assisted chemical vapor deposition (PACVD) process. The multilayer TiN/TiCN coatings on the substrate of the X37CrMoV5‐1 tool steel and the X22CrMoV12‐1 stainless steel were analyzed by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), calotest, and electrochemical methods. The analysis results show quite uniform TiN/TiCN coatings of high density, with similar surface topography and thickness, similar changes in the chemical composition across the thickness of the layer, and good adhesion to the substrates. Direct current (DC) and alternating current (AC) corrosion tests carried out in a solution of 3.5% NaCl have shown better corrosion resistance of the TiN/TiCN multilayer coating deposited on the substrate of stainless steel than the same coating deposited on the hot work tool steel. Electrochemical impedance spectroscopy (EIS) tests have shown that the coatings deposited on both steel substrates have a tendency towards local corrosion due to the existence of microporosity and defects in the coating microstructure. The manuscript describes a comparative study of corrosion behavior of the same PACVD produced gradient multilayer TiN/TiCN coating on two different steel substrates, the X37CrMoV5‐1 tool steel and the X22CrMoV12‐1 stainless steel. The multilayer TiN/TiCN coating were characterized by SEM, EDS, calotest, and electrochemical methods. The novelty of this work is characterization of coating on stainless steel and its comparison on tool steel. [ABSTRACT FROM AUTHOR]

In the present investigation, Titanium Carbonitride (TiCN) coating was deposited on a cemented carbide substrate, by means of Plasma Enhanced Physical Vapour Deposition (PEPVD) process. The microstructure of the deposited film was characterized using the Scanning Electron Microscope (SEM). Highly dense, less porous and uniformly distributed TiCN coating was observed on the coated surface. X-Ray diffraction analysis was carried out to access the phases present in the coated layer. The scratch resistance and hardness were measured using the scratch tester and Nanoindenter, respectively. The TiCN coating gives higher hardness and superior scratch resistance when compared to the substrate. The surface morphology of the coated film was characterized using the Atomic Force Microscope (AFM) and was found that the surface roughness was lesser for TiCN coating when compared to cemented carbide substrate. The intensified TiCN coating on the substrate will be useful in improving the surface behavior of cemented carbide cutting tool. [ABSTRACT FROM AUTHOR]

Although the applications of TiN and TiCN coatings are extensive, their mechanical and tribological properties are influenced by the substrates in which they are deposited. The present work is focused on the tribological performance of TiN and TiCN coatings on a working tool steel. Besides, adhesion and microhardness tests were carried out. The adhesion performance of both coatings resulted in class 1, according to CEN/TS 1071-8 standard, which allows observing the quality of adhesion. The composite microhardness was investigated by the analysis of relative indentation (β). Pin-on-disk tests were performed in dry and lubricated condition at 100 °C against tungsten carbide (WC). Low friction coefficients of μk = 0.08 for TiN and μk = 0.03 for TiCN were obtained in lubricated conditions. Wear mechanisms were analyzed by scanning electron microscopy (SEM). Abrasive wear was observed as the principal wear mechanism in dry condition, while in lubricated conditions wear signals seem to be scarcely noticeable. [ABSTRACT FROM AUTHOR]

This paper's aim is to suggest the Expert System for analyzing relative combat power in ground operations. Since relative combat power analysis in terms of comparing combat power of friendly forces with one of the enemy can determine how the commander and staffs operate their unit afterwards, it requires fast and rational decision-making process. However, it has relied on manual method so far though Tactical Information Communications Network(TICN) into which numbers of applications can be loaded has been developed over a decade. 3 methods for analyzing relative combat power were expressed as mathematic rules to be used knowledge in the expert system after reviewing previous studies, and it studied how intangible power as well as tangible were reflected on total combat power. The expert system that will be built using EXSYS Corvid tool is expected to lessen error rate, provide faster decision-making, and reflect both intangible combat power and tangible one by using an appropriate weights in analyzing relative combat power. Next research filed includes how to build expert systems related with military personnel and intelligence areas for fast and rational decision-making processes. [ABSTRACT FROM AUTHOR]

Rate-controlled sintering and spark plasma sintering are considered the most promising methods to produce dense nanoctructured ceramics. Refractory compounds are used to demonstrate the application of methods for controlling the densification rate and nonlinear heating and loading conditions to produce dense nanocomposites with 30-70 nm grains. The mechanical and tribological properties of ceramics with grains from 50 to 500 nm in size are compared. The effect of increase in the mechanical (5-15%) and tribological (to 50%) characteristics of nanocomposites consolidated by rate-controlled sintering and modified nonlinear spark plasma sintering is studied. Nanocomposites based on refractory nitrides and borides are regarded as promising materials for creating a new generation of cutting tools, as well as wear-resistant ceramics for wide application. [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate the effects of TiN and TiCN coating on corrosion resistance of pure titanium in the simulated oral environment. METHODS: The dental pure titanium commonly used in making removable denture was casted with 15 specimens, 10mmxl0mmxlmm in size. The specimens were randomly divided into group A, group B and group C. In the group B and group C, the specimens were coated with a thickness of 2.5p.m TiN and TiCN coating on surface by multi-arc physical vapor deposition, respectively. After microscopic energy spectrum analysis, microstructure and phase diffraction were examined by FESEM. Hardness and Young modulus of the various coating were determined by nanoindentation. The polarization curves of all specimens in artificial saliva were measured by PARSTAT'2273 electrochemical station. The data were analyzed with SPSS 17.0 software package for t test, one-way ANOVA and nonparametric test. RESULTS: Both the mierohardness and elastic modulus in the group B and group C were significantly superior to those in the group A (P<0.001). Meanwhile, both the microhardness and elastic modulus in the group C were significantly higher than those in the group B (P<0.01). Corrosion potential (Ecorr) was group A > group B > group C (P< 0.05). However, corrosion current density (Icorr) was significantly lower in the group A than in the group B, and in the group A than in the group C (P<0.01), while not significantly different between the B and group C (P>0.05).Breakdown potential (Ecorr) was group A

TiCN hard coatings present time-dependent tribological behavior with an initial running-in period (500-2000 cycles) marked by an elevated friction coefficient, followed by >10000 cycles with low-friction and wear at room temperature (RT) in ambient air. The mechanisms behind this behavior are not completely understood. Tribological tests performed at RT and at different relative humidity (RH) levels revealed that a minimum value between 15 and 25% RH is needed to trigger the low-friction regime at a sliding speed of 100 mm s. By in situ observations of transfer film growth, it could be observed that third body material is formed during this running-in period by plowing of the coating and shearing of the removed material. The appearance and thickening of the transfer film marks the beginning of the steady-state low-friction regime where the velocity is accommodated by interfacial sliding. At this stage in the tribological test, the recorded Raman spectra indicated the presence of C-H bonds in the wear track. Use of in situ analytical tools during wear tests provided insights with respect to tribological phenomena that were not available by conventional, post-mortem analysis methods. [ABSTRACT FROM AUTHOR]

The tribological properties of tools and components are improved by wear resistant coatings deposited by thermochemical processing (nitriding, nitrocarburizing) or physical vapor deposition (PVD) technologies. The properties gradient between the very hard and brittle layer and the soft, ductile, but hardenable matrix material can be significantly improved by previous or subsequent electron beam hardening (EBH). The hardness of matrix material is increased by martensitic transformation up to a certain depth, which results in better load support for the hard coating layer. The influence of the tempering stability of the steels investigated and the chemical and structural stability of the coatings on the chosen sequence of treatments is discussed. [ABSTRACT FROM AUTHOR]

Selection of tool steel grades and Physical Vapour Deposition (PVD) coatings is of key importance for the tool longevity. Therefore, it is very important to recognize all present wear mechanisms in tool operation and select the most influential one, which enables proper selection of the tool steel grade for the active tool positions. The case study of certain tool steel selections has been provided, along with presentation of the exploitational behavior of PVD coatings in certain cases. The feedback received from exploitation of tools is included. [ABSTRACT FROM AUTHOR]

Metal matrix composites, based on 316L stainless steel and reinforced with TiC and TiCN particles, were manufactured following a powder injection moulding route: mixing, preparation of feedstock, moulding, debinding and sintering. The 316L stainless steel and carbide powders were dry mixed and moulded with wax based binder. The critical powder loading for injection moulding was 62·5 vol.-% for all samples. Binder debinding was performed by solvent and thermal method. After debinding, the samples were sintered at 1250 and 1385°C for 1 h in pure H2. Metallographic studies were conducted to extend densification and the corresponding microstructural changes. The sintered samples were characterised by measuring tensile strength, hardness and wear behaviour. Wear loss was determined for all samples after wear tests. All powder, fracture surfaces of moulded and sintered samples, and worn surfaces of all the samples, were examined using scanning electron microscope. The sintered density of injection moulded 316L stainless steel samples, reinforced and unreinforced, increases with increasing sintering temperature. The addition of TiC and TiCN improves the hardness and wear resistance with increasing sintering temperature. [ABSTRACT FROM AUTHOR]

The present study compares the effect of TiC and TiCN additions on the densification and mechanical properties response of injection moulded 316L stainless steels. The sintered density of straight as well as TiC and TiCN reinforced injection moulded 316L stainless steels increases with increasing sintering temperature. The addition of TiC and TiCN improves the hardness and wear resistance with increasing sintering temperature. [ABSTRACT FROM AUTHOR]

TiCN coating, owing to its superior wear-resistance, has been frequently applied in many fields. TIGN thick coating was first prepared by reactive plasma spraying. The phase composition, microstructure and tribological properties of the TiCN coating were investigated in this research. Experimental results show that the microstructure of the TiCN coating was quite dense,and there was also a little ambunt of titanium oxides within the coating. By XPS analysis, Ti-C and Ti-N bonds were detected in the coating. The TiCN coating exhibited superior wear-resistance. The failure mechanism was attributed to the ad- hesive wear, the grinding of TiCN hard-grain, as well as the coating failure by oxidation. There were more Fe, Cr, 0, etc. in the failure zone, suggesting that the corrosion propagated gradually from surface to interior. [ABSTRACT FROM AUTHOR]

Titanium Carbonitride (TiCN), a new high hardness and wear-resistant material, has been applied widely in many fields. TiCN coating was first fabricated using reactive plasma spraying (RPS) technology in the reactive chamber that was filled with nitrogen and acetylene (N2 and C2H2) in this study. The microstructure and the phase composition of the coatings were analyzed by SEM and XRD. More chemical information of surface was analyzed by XPS. The Vickers microhardness of TiCN coating is 1659.11 HV100g, and the cross-section of the coating shows a conspicuous phenomenon of indentation size effect. [ABSTRACT FROM AUTHOR]

Today the tool industry on a worldwide basis uses hard, wear-resistant, and low-friction coatings produced by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, chemical-vapor deposition (CVD), and physical vapor deposition (PVD). In the current work, two different coatings, nitrocarburized (CN) and titanium carbonitride (TiCN) on M2-grade tool steel, were prepared by commercial diffusion and PVD techniques, respectively. Properties such as thickness, roughness, and hardness were characterized using a variety of techniques, including glow-discharge optical emission spectrometry (GD-OES) and scanning electron microscopy (SEM). A crossed-cylinders wear-testing machine was used to investigate the performances of both coatings under lubrication. The effect of coatings on the performance of lubricants under a range of wear-test conditions was also examined. Degradation of lubricants during tribological testing was explored by Fourier transform infrared (FTIR) spectroscopy. [ABSTRACT FROM AUTHOR]

The development of cemented carbides nowadays is aimed at the application and sintering of ultrafine and nano-sized powders for the production of a variety of components where excellent mechanical properties and high wear resistance are required for use in high temperature and corrosive environment conditions. The most efficient way of increasing the tribological properties along with achieving high corrosion resistance is coating. Using surface processes (modification and/or coating), it is possible to form a surface layer/base material system with properties that can meet modern expectations with acceptable production costs. Three coating systems were developed on WC cemented carbides substrate with the addition of 10 wt.% Co using the plasma-assisted chemical vapor deposition (PACVD) method: single-layer TiN coating, harder multilayer gradient TiCN coating composed of TiN and TiCN layers, and the hardest multilayer TiBN coating composed of TiN and TiB2. Physical and mechanical properties of coated and uncoated samples were investigated by means of quantitative depth profile (QDP) analysis, nanoindentation, surface layer characterization (XRD analysis), and coating adhesion evaluation using the scratch test. The results confirm the possibility of obtaining nanostructured cemented carbides of homogeneous structure without structural defects such as eta phase or unbound carbon providing increase in hardness and fracture toughness. The lowest adhesion was detected for the single-layer TiN coating, while coatings with a complex architecture (TiCN, TiBN) showed improved adhesion. [ABSTRACT FROM AUTHOR]

In this study, the average residual stresses were determined in hard PVD nACRo (nc-AlCrN/a-Si3N4), nACo (nc-AlTiN/a-Si3N4), AlCrN, TiAlN, and TiCN commercial coatings through the deflection of the plate substrates and the simultaneous measurement of length variation in thin-walled tubular substrates. The length measuring unit was used for the measurement of any length change in the tubular substrate. A change in tube length was reduced to the deflection of the middle cross-section of the elastic element for which deformation was measured using four strain gauges. The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM), and a determination was made of the chemical composition of the coatings and substrate by means of energy dispersive X-ray spectroscopy (EDS). The values of average compressive residual stresses, as determined by both methods, were very high (with a variation of between 2.05 and 6.63 GPa), irrespective of coating thickness, but were dependent upon the shape of the substrate and on its position in relation to the axis of the rotating cathode. The thicknesses of the coatings that were deposited on the plates with two parallel fixings (such as the nACRo coatings on the front surface at 6.8 μm and on the rear surface at 2.9 μm) and on the tubular substrates (10.0 μm) were significantly different. The higher average compressive residual stresses in the coating correlate to the higher average relative wear resistance that was obtained during field wear testing. [ABSTRACT FROM AUTHOR]

The submitted contribution deals with the wear of thin coatings applied to convex–concave gearings for gear made from C45E steel. The influence of the tribological characteristics (friction coefficient, wear, adhesion and hardness) of the TiN, TiCN coatings and the combined coating of TiCN + MoS2 on convex–concave gearing is described, from the aspects of scuffing formation. Scuffing tests were done on C–C gears. Coatings were applied by arc–ion-plating (AIP) and magnetron sputter-ion-plating (MSIP) methods. The thickness of the deposited coating and its chemical composition were determined by SEM and EDX analysis. Load-bearing capacity was evaluated by a Niemann tester. The TiCN + MoS2 combined coating with the MoS2 layer on the top reached the lowest coefficient of friction. However, after a rapid wearing of the MoS2 layer, this value dropped to a comparable value of TiCN. The nano-hardness of the TiCN layer was higher in comparison with TiN. Thin and soft MoS2 layers cracked already at lower load levels and separated from the substrate at the 5th load stage. The formation of scuffings for selected coatings documented in this article was solved for convex–concave gearing working also in interaction with Biogear S 150 and Biohyd MS 46 oils. [ABSTRACT FROM AUTHOR]