Titanium Carbonitride Research Articles

Influence of processing on the microstructural evolution and multiscale hardness in titanium carbonitrides (TiCN) produced via field assisted sintering technology

Titanium carbonitride (TiCN) is an advanced, high-performance hard ceramic of great commercial importance that has been widely developed and employed. Nonetheless, it has only been in recent years that binderless titanium carbonitride bulk ceramics have been successfully fabricated using field-assisted sintering technology (FAST). However, the underlying structure-processing-property-performance relationships have yet to be fully evaluated, especially concerning indentation hardness of these materials across a broad range of loads and deformation length scales. In this work we aim to address these fundamental relationships and characterize the multiscale hardness phenomena in detail. It was found that the effects of soak temperature and time directly impacted the sintered microstructure and were reflected in the observed mechanical properties over various loads. Valuable insight into the load-dependence of hardness distributions, sensitivity/correlation with elastoplastic parameters, and multiscale parameterization were developed using micro-/nanoindentation. Particularly, the load-dependent hardness sensitivity and resolvability demonstrate a fundamental tradeoff with respect to the manifested mechanical response influenced by the presence of underlying heterogeneities. These new insights relating the interplay of compositional/microstructural evolution with FAST processing parameters and multiscale hardness are an important step in advancing next-generation hard ceramics.

INVESTIGATION OF THE EFFECT OF NANOCOATINGS ON THE WEAR-RESISTANCE OF SOCKET CARBIDE MILLS

The results of studies of the wear-resistance of socket mills made of hard alloys in the processing of hard-to-process structural chromium steels are presented. The technology of hardening of cutting teeth with a wear-resistant coating obtained by the Physical Vapour Deposition method is considered. The influenceof the structure of the hardening composite coating based on titanium nitrides and carbonitrides on the mechanical characteristics and working capacity of the tool is shown. The nature of wear and brittle destruction of the working surfaces of the tool under intermittent cutting conditions and the influence of wear-resistant coatings on the thermal and stress state of the cutting wedge in the contact zone are investigated.

Fabrication and characterization of highly thermal conductive Si3N4/diamond composite materials

A novel composite materials using silicon nitride (Si3N4) as the substrate and diamond particles as the reinforcement phase were developed to increase both thermal conductivity and mechanical properties. The Ti coating on the surfaces of the diamond particles facilitated the formation of a titanium carbonitride (TiCiN1-i) interface between the two constituents during sintering, creating a strong bonding for high thermal conduction at the diamond-Si3N4 interface and inhibiting the graphitization of diamond during the sintering process. Furthermore, a sandwiched material design was made whereby Si3N4 and Si3N4/Ti-coated diamond layers were stacked alternately to endow the composites with a directional heat conduction characteristic. The thermal conductivity of the fabricated Si3N4/diamond composites increased by up to 272.87 % compared to that of commercially available Si3N4, making them excellent candidates for thermal management materials required in high-performance electronic devices.

Features of the structure of steels of various compositions for the manufacture of pipes transporting hydrogen sulfide-containing natural gas

The paper presents the results of studies of the structural features of plate rolled products of low-carbon pipe steels 04KhNDB, 05KhGB and 06GNFB differing in the basic composition and content of microalloying elements. In the production of industrial rolled products for each steel under study, the choice of rolling temperatures was made individually, but in the same way from the point of view of structure formation. The completion of the finishing stage of rolling was carried out in the austenite region near the temperature of the beginning of the phase transformation, the beginning of cooling - from the austenite region, in order to form a homogeneous structure and exclude the formation of structural banding. The steels have a similar microstructure after rolling, but the structure of the axial zone, which is basically the weak point in tests in hydrogen sulfide, is different. The microstructure of steel 04KhNDB is almost uniform in thickness and a slight segregation of manganese has little effect on the hardness of the axial zone. In steels 05KhGB and 06GNFB, segregation of manganese and an increase in the proportion of intermediate transformation products in the axial zone leads to the formation of elongated regions with increased hardness. This is most pronounced in steel 06GNFB, in which cracks were revealed after testing for hydrogen cracking in accordance with the NACE TM0284 method. It has been established that with a homogeneous microstructure in the axial zone of rolled products without areas of increased hardness and in the absence of manganese sulfides in it, large inclusions of titanium and niobium carbonitrides do not adversely affect the resistance to hydrogen cracking.

Analysis of the use of magnesium-containing additives in the charge of iron flux in order to reduce CO2 emissions

The growing requirements for the quality of finished steel products oblige to obtain steel with a low content of harmful impurities, especially sulfur. The main charge for steel production in the conditions of JSC EVRAZ NTMK is vanadium iron, the external desulfurization of which leads to large losses of valuable vanadium. Therefore, the smelting of iron with a low sulfur content is an urgent task. The main way to reduce sulfur in iron is to increase the basicity of the slag (B2), but MgO is the best desulfurizer. The paper evaluates the effectiveness of the use of various magnesium-containing materials in the conditions of the blast-furnace stage of JSC EVRAZ NTMK, taking into account CO2 emissions. The possibility of replacing limestone in the iron flux charge with dolomite, as well as with steel converter slag, is considered. Both materials will increase the proportion of MgO in blast-furnace slag, however, the use of dolomite is accompanied by a two-fold increase in CO2 emissions compared to limestone. Converter steel slag (CSS) does not contain carbonates, thus eliminating the formation of CO2 during the limestone decomposition. An additional advantage of CSS is its high content of valuable vanadium and manganese. The effect of an increase in MgO in slag on its melting point is considered. It has been established that an increase in the proportion of MgO to 14% will not cause difficulties in the processing of blast-furnace smelting products and will reduce the sulfur content in iron and the formation of titanium carbides and carbonitrides.

Performance of Multilayered Nanocoated Cutting Tools in High-Speed Machining: A Review

In machining processes, cutting tools play a dominant role in producing quality products. The quality of finished goods is directly related to the cutting tool condition. Several types of research have been carried out in cutting tool condition monitoring. On the other hand, the manufacturing industries should be aware of the cutting tool selection, operating conditions, and performance of cutting tools. This article emphasizes the performance of coated cutting tools and tool materials for various machining operations. Nowadays, the nanocoating of CNC tool inserts increases the wear resistance, vibration emissions, metal removal rate, etc. These coating techniques influence the manufacturing industry to increase the productivity and quality of the finished goods and reduce the machining cost. The performance of thin film multilayered coatings such as TiN, TiAlN, AlTiN, Ti, and TiCN on plain silicon carbide tool inserts is revealed by the researchers to guide the manufacturing industry for proper tool selection and standard machining inputs for metal removal operation. The influence of coating material such as TiBN, TiN, TiAlN, and CrAlSiN in cutting tools leads to increase the life time of the cutting tools, which decreases the material sticking and cutting forces. Titanium carbo nitride is wear-resistant and corrosion-resistant. Compared to TiCN, TiAlN is harder due to the higher hardness of 32 GPa. This article concludes the material selection based on the work piece material which yields good metal removal with less cutting forces. The article concludes the cutting material selection based on the work piece for machining operations.

Вплив модифікування на руйнування аустенітних неіржавіючих сталей при динамічних навантаженнях

The paper presents the results of studying the cold resistance of cast stainless steels of austenitic grade and developed mathematical models showing the effect of cerium, boron, vanadium and copper on cold resistance, which is associated with austenite grain size, carbide phase and ferrite content in austenite after quenching, particle volumes, size and distance between particles of oxides, sulfides, titanium carbonitrides and the total content of non-metallic inclusions in cast stainless steel. It was established that with complex microalloying and modification of Ce, B, V and Cu, the impact toughness of stainless steels increases by 2.7-3.1 times, as a result of the increase of nucleation and crack propagation work. It showed that the crack nucleation and their development is associated with non-metallic inclusions, while in the original steels around non-metallic inclusions significant zones of brittle failure are observed, and in the fracture of complex microalloyed and modified steels there are practically no areas of brittle failure around non-metallic inclusions. It was established that the impact toughness and crack initiation and propagation of the investigated stainless steels are determined by the patterns of changes in such structural factors as the size of the austenite grain, the content of the carbide phase and ferrite in the austenite after quenching, the volume fraction, the size and distance between oxide particles, titanium sulfides and carbonitrides, as well as the total content of non-metallic inclusions. Mathematical models of the influence of structural factors have been developed, which show the predominant influence of non-metallic inclusions on the process of destruction of stainless steels under dynamic loads, in comparison with other structure characteristics, in conditions of negative temperatures is shown. It is established that the mechanism of influence of Ce, B, V and Cu on this process is connected, mainly, with dispersion of oxides and their more homogeneous distribution. Keywords: steel, toughness, fracture work, crack formation, crack propagation, modification.

In situ grown two-dimensional TiO2/Ti3CN MXene heterojunction rich in Ti3+ species for highly efficient photoelectrocatalytic CO2 reduction

Converting CO2 into chemicals is a promising avenue to mitigate the energy crisis and global warming. Herein, two-dimensional (2D) heterojunctions of TiO2/Ti3CN MXene were fabricated through a facile hydrothermal oxidation method and used as the photocathode in photoelectrocatalytic (PEC) CO2 reduction. The in situ grown TiO2/Ti3CN heterojunctions demonstrate excellent light absorption abilities, possess large specific surface areas and Ti3+ species, which are beneficial to the generation and transportation of photoelectron-hole pairs. In a new PEC system of Pd@TiO2/Ti3CN||SCE||BiVO4, formate, methanol and C2 of ethanol were obtained as the major reduction products, with the maximum and total formation rate of 45.6 μM cm−2h−1. Furthermore, density functional theory (DFT) calculations indicate that TiO2/Ti3CN heterojunction can spontaneously activate CO2 and stabilize the key reaction intermediates for facilitating HCOOH production. This research highlights the great prospect of titanium carbonitrides MXene in the green energy conversion field.

On the influence of physical vapor deposited thin coatings on the low-cycle fatigue behavior of additively processed Ti-6Al-7Nb alloy

The tensile and fatigue properties of laser powder bed fused Ti-6Al-7Nb are improved by physical vapor deposition (PVD). Thin coatings of titanium nitride (TiN), titanium carbonitride (TiCN), and silver-containing amorphous carbon (a-C:Ag) are deposited by magnetron sputtering. Tensile and strain-controlled low-cycle fatigue tests with various total strain amplitudes are performed. The coatings increase the tensile strength and decrease the breaking elongation. The low-cycle fatigue performance of the PVD-coated conditions, except for the a-C:Ag coating, is improved. The coatings considerably enhance tensile strength and fatigue resistance due to their high residual compressive stresses and increased surface hardness.

Insight into tribological and corrosion behaviour of binderless TiCxNy ceramic composites processed via pulsed electric current sintering technique

The study presents the corrosion behaviour and wear response of pulsed electric current sintered binderless TiC 50 N 50 , TiC 70 N 30 , and TiC 90 N 10 based ceramic composites, consolidated by spark plasma sintering (SPS), and the relative densities were evaluated using the Archimedes principle. The microstructural evolutions of the sintered samples were examined through various microscopy techniques, and their susceptibility to corrosion in aggressive chloride environment was assessed using open circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The microstructural examination of the specimens showed the presence of different phases within the titanium carbonitride (TiCN) cermets. The wear resistance evaluated using the frictional coefficient (COF) and calculated wear rate showed that the specimens exhibited an improved resistance. The specimens further showed enhanced resistance to corrosion in the test electrolyte, as the TiC 50 N 50 cermet displayed enhanced resistance to the aggressive chloride ions in comparison to the other specimens.

Influence of Physical Vapor Deposition on High-Cycle Fatigue Performance of Additively Manufactured Ti-6Al-7Nb Alloy

Load-bearing permanent implants, such as hip or knee joint replacements, are permanently loaded in the human body and must withstand considerable high loading cycles. The characteristic properties of additively manufactured Ti-6Al-7Nb, manufactured by laser powder bed fusion (LPBF), such as a rough surface and high residual stresses, have a detrimental effect on the fatigue behavior of such components. Functional physical vapor deposition (PVD) coatings and heat treatments offer the possibility to influence these properties. For this reason, the effects of stress-relief heat treatment (SR; 600 °C/4 h) and three PVD coatings (titanium nitride (TiN), titanium carbonitride (TiCN), and silver-containing amorphous carbon (a-C:Ag)) on the mechanical properties, in terms of high-cycle fatigue, are identified. Wöhler curves are determined and the staircase procedure ascertains the fatigue strengths. The fatigue strengths increase compared to the as-built condition by 105.4% (SR), 44.2% (TiN), 31.1% (TiCN), and 2.6% (a-C:Ag). Fracture surfaces are analyzed by scanning electron microscopy and show LPBF characteristic defects such as pores. The surfaces are partially divided into forced and fatigue fracture, the latter characterized by fatigue striations. Overall, PVD coatings, and especially SR, lead to an improved high-cycle fatigue behavior.

Вплив комплексного модифікування на структуру й властивості жароміцного нікелевого сплаву

In this work, a study of the influence of complex modification of the ZhS3DK-VІ nickel-based heat-resistant super alloy was conducted. The modification was performed out according to different technological schemes: with highly dispersed titanium carbonitrides Ti[Ti(C,N)] particles, with Ti [Ti(C,N)]+CoAl2O4 and Ti[Ti(C,N)]+CoAl2O4+Ni-Y complex that made it possible to investigate the specifics of the influence of the volume modifier Ti[Ti(C,N)] separately, and its complex effect with surface modifierCoAl2O4 and rare earth metals (with Ni-Y master alloy use) in the macro- and microstructure of a heat-resistant nickel alloy. It was shown that the use of modifiers allows for significant refining of macrograins, and the greatest effect was obtained with Ti[Ti(C,N)]+CoAl2O4 and Ti[Ti(C,N)]+Ni-Y+CoAl2O4complexes. Microstructure study allows to show that the value of interdendritic distances in both the case of modification with Ti[Ti(C,N)] and Ti[Ti(C,N)]+Ni-Y+CoAl2O4 complexes essignificantly decreased, from 100…130 μm to 80...120 μm, which is the result of many nuclei formation during crystallization in the volume of the alloy and with highly intense heat transfer from the melt by CoAl2Omodified ceramic mould after melt pouring. Based on the results of the influence of various types of modification on the microstructure of the alloy under study, it was established that modification according to all schemes allows obtaining carbides of smaller sizes, but grown sizes of carbonitrides was observed. Globular particles of carbide and carbonitrides are evenly located along the cross-section of the samples under study. In all cases of modification, a decrease in the value of the shrinkage microporosity was observed. The mechanical properties of the specimens after standard heat treatment shows, that modification with complexes under study allows provide mechanical properties that meet the specification requirements. The best complex of alloy mechanical properties at room temperature, fracture toughness and stress-rupture strength provides with Ti[Ti(C,N)]+Ni-Y+CoAl2O4 modifiers complex.

Electrocatalytic Self‐Supported‐Electrode Based on CoxNi1‐xP/TiC0.5N0.5 for Enhancing pH‐Universal Hydrogen Evolution Electrocatalysis

AbstractThe industrial application of powder‐based catalytic electrodes is heavily restricted by powder shedding, inhibition of active sites, and poor long‐term stability. Herein, a porous titanium carbonitride (TiC0.5N0.5) ceramic substrate with open straight finger‐like holes is first made by a simple approach of phase‐inversion tape‐casting and pressureless sintering, and then a CoxNi1‐xP active layer is in situ formed by a hydrothermal technique and phosphorization to achieve integrated CoxNi1‐xP/TiC0.5N0.5 self‐supported ceramic electrodes. Electrochemical tests reveal that the optimized Co0.9Ni0.1P/TiC0.5N0.5 electrode exhibits overpotentials of 76.5 and 79.8 mV at 10 mA cm−2, Tafel slopes of 47.3 and 40.5 mV dec−1, in 0.5 m H2SO4 and 1 m KOH, respectively. Furthermore, its superior long‐term stability and resistance to corrosion can be achieved for more than 20 h in both media at 100 mA cm−2. In addition, the Co0.9Ni0.1P/TiC0.5N0.5 electrode has much better performance than Pt/C at high current density in neutral media. Density functional theory calculations confirm that the Ni substitution of 1/10 Co in CoP leads to the more optimal |ΔGH*| among the CoxNi1‐xP catalysts. Compared with other CoP or NiP‐based electrodes, the Co0.9Ni0.1P/TiC0.5N0.5 electrode benefits from high strength, unique pore structure, tight and compatible bonding, and high hydrophilicity.

Numerical analysis for mechanical behaviour of beams made by composite and functionally graded materials

Functionally graded materials are important in laboratory and industry. These materials have opened a new area of research. These functionally graded materials can be produced as a result of composite material by the adding more materials to get desired properties to make it perfect for suitable applications. In this paper, the focus is on the modelling of functionally graded material that is developed to resist wear by any friction or erosion by any liquid. Cemented Carbide (WC) was selected as a composite material that is commonly used in industrial or lab. Before developing the model of functionally graded material (FGM), a detailed study has been carried out on the composite material using the finite element method to find a numerical solution and compared it to the exact one. The analytical solution was obtained by using MATLAB and numerical solution by ANSYS. Besides these software’s SolidWorks and SkyCIV programs were utilized for analysis and plotting purposes. At the end of the project, one layer titanium carbonitride (TiCN) was added to one face and the same layer was added to the four faces to make the comparison between the two cases to select the best model using the results of a total of deformation.

Вплив термічної обробки на механічні властивості модифікованих неіржавіючих сталей

The paper presents the results of the study of the influence of structure on the mechanical properties of microalloyed and modified austenitic stainless steels. It is shown that the mechanical properties of cast austenitic stainless steels with a probability of 95 % and an error of 0.46 to 13.2 % are determined by such structural parameters as austenite grain size, carbide phase and ferrite content in austenite after quenching, quantity, size and distance between oxide, titanium sulfides and carbonitrides particles. Mathematical models of the structure influence on the yield strength, reduction of area and toughness of stainless steels are built. The structure parameter effectiveness is shown and it is shown that to increase the efficiency of strength, reduction of area and toughness of stainless steels at normal temperature structural factors affect in the following sequence: austenite grain size, volume fraction, size and distribution of titanium carbonitrides and sulfides, the total quantity of non-metallic inclusions, carbides and ferrite in austenite after hardening of stainless steel, as well as the volume fraction, size and distribution of oxide inclusions. Keywords: steel, structure, mechanical properties, strength, ductility, toughness.

Regulation of structural and terahertz properties of TiC nanoparticles by carbon-coating and nitrogen-doping

Carbon-coated titanium carbide nanocomposites (TiC@C NCs) were synthesized by arc discharge plasma under an atmosphere of Ar and CH4 gas, and nitrogen-doped carbon-coated titanium carbonitride nanocomposites (Ti(C,N)@NC NCs) were also obtained using a mixture gas of N2 and CH4. Terahertz (THz) optical and dielectric properties of these nanostructures were investigated using a THz time-domain spectrum system, and the extracted conductivity was analyzed to understand the transport mechanism. The dielectric response in these nanostructures is dominated by ionic polarization with a relaxation behavior, and absorption characteristic is free carrier absorption dependent on conductivity. Ti(C,N)@NC NCs achieve the enhanced dielectric response and high absorption loss due to nitrogen-doping increasing charge disorder and conductivity. AC conductivities of the samples were fitted to the universal power low function and indicated that the transport mechanism is electronic hopping.

Cermet Systems: Synthesis, Properties, and Applications

Cermet is an advanced class of material consisting of a hard ceramic phase along with a metallic binding phase with the combined advantages of both the ceramic and the metal phase. The superior properties of this class of materials are particularly useful in high-temperature, tribological, and machining applications. This review paper seeks to provide a comprehensive overview of the various cermet systems. More specifically, the most commonly used cermet systems based on tungsten carbide (WC), titanium carbide (TiC), titanium carbonitride (TiCN), and aluminum oxide (Al2O3) are discussed based on their development, properties, and applications. The effect of different metallic binders and their composition on the tribological and mechanical properties of these cermet systems is elaborated. The most common processing techniques for cermet systems, such as powder metallurgy (PM), reaction synthesis (RS), thermal spray (TS), cold spray (CS), and laser-based additive manufacturing techniques are discussed. The influence of the processing parameters in each case is evaluated. Finally, the applications and challenges of cermet systems are summarized.

Study on the Hot Deformation Behavior of Stainless Steel AISI 321

In this study, the hot deformation behavior of austenitic Ti-modified AISI 321 steel with a relatively high content of carbon (0.07 wt.%) and titanium (0.50 wt.%) was studied in the temperature range of 1000–1280 °C and strain rates in the range of 0.01–1 s−1. Hot deformation was carried out with uniaxial compression of cylindrical specimens on a Gleeble 3800 thermomechanical simulator. It is shown that the flow stress increased with a decrease in the deformation temperature and an increase in the strain rate. The shape of the stress-strain curves indicates that, at high temperatures and low strain rates, the hot deformation of AISI 321 steel was accompanied by dynamic recrystallization. The passage of dynamic recrystallization was confirmed by microstructural studies. Hyperbolic sine type of constitutive equation with deformation activation energy Q = 444.2 kJ·mol−1 was established by analyzing the experimental flow stresses. The power-law dependences of the critical strain necessary for the onset of dynamic recrystallization and the size of recrystallized grains on the Zener–Hollomon parameter were established. The value of the parameter Z = 5.6 × 1015 was determined, above which the dynamic recrystallization was abruptly suppressed in the steel under study. It is speculated that the suppression of dynamic recrystallization occurs due to dispersed precipitates of titanium carbonitrides.

Effect of Heat Treatment on the Microstructure and Hardness of Ni-Based Alloy 718 in a Variable Thickness Geometry Deposited by Powder Fed Directed Energy Deposition

Feature addition to existing parts is a trending application for Directed Energy Deposition (DED) and can be used to add complex geometry features to basic forged geometries with the aim to reduce and simplify the number of processing steps as machining and assembling. However, the mechanical properties of as-deposited Inconel 718 fabricated by Powder-fed Directed Energy Deposition (Powder-fed DED) are far lower than the relevant specifications, making it necessary to apply different heat treatment with the purpose of improving deposited material performance. In addition, the effects of heat treatments in both variable thickness deposited geometry and forge substrate have not been studied. In this study, the effect of heat treatment within the Aerospace Materials Specifications (AMS) for cast and wrought Inconel 718 on the microstructure and hardness of both the Ni-Based Alloy 718 deposited geometry and substrate are analyzed in different parts of the geometry. The microstructure of all samples (as-deposited and heat-treated) is analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS), confirming the formation of aluminum oxides and titanium nitrides and carbonitrides in the deposited structure.

Deposition of carbonitride titanium coatings by magnetron sputtering and its effect on tribo-mechanical properties

Metal parts in machinery often fail as a result of damage caused by wear and tear, resulting in the loss of functionality of the products. Thin film solid nitride coatings are used to improve the wear resistance and service life of parts and are considered to be effective. The article presents a brief overview of modern literature in the field of obtaining wear resistant coatings of titanium carbonitride by using magnetron sputtering. The review presents a detailed assessment of the scientific results obtained depending on the deposition parameters and the conditions for obtaining coatings. The results of the coefficient of friction, wear rate of the coating and counterbody, nanohardness and adhesion force of coatings obtained by magnetron sputtering and its modifications are shown. The influence of alloying elements on the mechanical and tribological properties of titanium carbonitride coatings is considered. Recent advances in the production of titanium carbonitride coatings with improved wear characteristics are discussed.