Titanium Carbide TiC Research Articles

New Die-Compaction Equations for Powders as a Result of Known Equations Correction: Part 2—Modernization of M Yu Balshin’s Equations

Based on the generalization of M. Yu. Balshin’s well-known equations in the framework of a discrete model of powder compaction process (PCP), two new die-compaction equations for powders have been derived that show the dependence of the compaction pressure p on the relative density ρ of the powder sample. The first equation, p=w(1−ρ0)(n−m)·(ρ−ρ0)n(1−ρ)m, contains, in addition to the initial density ρ0 of the powder in die, three constant parameters—w, n and m. The second equation in the form p=H1−ρ0b−c·ρ−ρ0b1−ρ0c−aρ−ρ0c also takes into account the initial density of the powder and contains four constant parameters H, a, b, and c. The values of the constant parameters in both equations are determined by fitting the theoretical curve according to these equations to the experimental powder compaction curve. The adequacy of the PCP description with these equations has been verified by approximating experimental data on the compaction of various powders, including usual metal powders such as iron, copper, and nickel, highly plastic powders such as tin and lead, a mixture of plastic powder (Ni) with non-plastic powder (Al2O3), nickel-plated alumina powder, as well as powder of a brittle compound, in particular titanium carbide TiC. The proposed equations make it possible to describe PCP with high accuracy, at which the coefficient of determination R2 reaches values from 0.9900 to 0.9999. The four-constant equation provides a very accurate description of PCP from start to finish when the density of the samples stops increasing once the pressure increases to an extremely high level, despite the presence of porosity.

Processing and characterization of aluminium reinforced metal matrix composite

Indeed, in the areas of aerospace, maritime, transportation, military, and structural applications, composite plays a crucial role in material science. It is composed of two or more phases that are physically and chemically different. The composite exhibits hybrid properties compared to those of the separate components. Materials that are built on a metal matrix are known as metal matrix composites (MMC). The reinforcing component is typically spread in the matrix or continuous component. MMC focuses primarily on applications that need wear resistance and moderately high strength. Aluminum matrix composite reinforced with (Titanium Carbide) TiC particulate is effectively manufactured among MMCs utilising a modified stir casting technique at five various weight% of TiC particle addition. Weight fractions of 3%, 4%, 5%, 6%, and 7% were used. The presence of TiC in the cast aluminium matrix was discovered by the use of colour optical graphs, XRD, and EDS investigation. The ultimate tensile strength clearly improved as the percentage of TiC addition was raised, as seen by the results of the microhardness and tensile tests at 7% of TiC.

Studying the Plastic Deformation of Cu-Ti-C-B Composites in a Favorable Stress State.

Composites with a copper matrix attract the attention of researchers due to their ability to combine high ductility, heat conductivity, and electrical conductivity of the matrix with the high hardness and strength of the reinforcing phases. In this paper, we present the results of studying the effect of thermal deformation processing of a Сu-Ti-C-B composite produced by self-propagating high-temperature synthesis (SHS) on its ability to deform plastically without failure. The composite consists of a copper matrix and reinforced particles of titanium carbide TiC (sized up to 1.0 μm) and titanium diboride TiB2 (sized up to 3.0 μm). The composite hardness is 60 HRC. Under uniaxial compression, the composite starts to deform plastically at a temperature of 700 °C and a pressure of 100 MPa. Temperatures ranging between 765 and 800 °C and an initial pressure of 150 MPa prove to be the most effective condition for composite deformation. These conditions enabled a true strain of 0.36 to be obtained without composite failure. Under higher strain, surface cracks appeared on the specimen surface. The EBSD analysis shows that dynamic recrystallization prevails at a deformation temperature of at least 765 °C; therefore, the composite can plastically deform. To increase the deformability of the composite, it is proposed to perform deformation under conditions of a favorable stress state. Based on the results of numerical modeling by the finite element method, the critical diameter of the steel shell is determined, which is sufficient for deformation of the composite with the most uniform distribution of the stress coefficient k. Composite deformation in a steel shell under a pressure of 150 MPa, at 800 °C, is experimentally implemented until a true strain of 0.53 is reached.

Micromechanical properties and transverse rupture strength of a Cu-Ti-C-B composite

The paper presents the results of studying the microstructure, chemical and phase compositions of a Cu-Ti-C-B composite produced by self-propagating high-temperature synthesis (SHS). It has been found that the matrix of the composite is a titanium-doped copper-based solid solution. Titanium carbide TiC and titanium diboride TiB2 are the strengthening phases. Single particles of boron carbide B4C unreacted in SHS have been detected, with the hardness 3332 HV 0.1. The composite density is 6.8 g/cm3. The overall hardness of the composite is 60 to 62 HRC. The uneven distribution of the constituents in the volume of the composite causes the uneven distribution of its micromechanical properties. The most ductile constituent of the composite is the Cu+TiC mechanical mixture, which ensures the high ductile fracture energy of the composite in transverse bending testing. On the fracture surface, at the interface separating the B4C particles and the copper-based solid solution, there are microvoids indicating the start of microcracks growth. The strength of the composite is Rbm30 = 820 MPa.

Synthesis and Sintering of Tungsten and Titanium Carbide: A Parametric Study

The three primary steps in the production of tungsten carbide WC and titanium carbide TiC powders are the preparation of the green mixture, carbidization by furnace annealing, and ball milling of the annealed products. This work performed a comprehensive parametric investigation of these three steps. The impact of several factors was examined including the carbon precursor, the mass and diameter of the milling bodies (balls), the milling time and speed, the temperature and length of the annealing process, the height of the powder in the furnace boats, and the rate at which the furnace boats move. Regression models for every stage of the process were verified by 10-fold validation and used to optimize the synthesis sequence, resulting in high-quality WC and TiC with a grain size below 2 microns and a content of free carbon below 0.1%. Additionally, solid solution (W,Ti)C was fabricated by mechanochemical synthesis from the elemental mixtures; however, further modification of this technique is necessary because of the observed relatively high concentration of residual free carbon (0.2–0.8%) and contamination by Fe.

Features of phase and structure formation in obtaining high-entropy alloy of Fe-Ti-Cr-Mn-Si-C system from a powder mixture of ferroalloys

The peculiarities of the structure and phase composition of the high-entropy alloy of the TiCrFeMnSiC system obtained from the powder mixture of ferrotitanium, ferrochrome and ferrosilicon-manganese ferroalloys are considered in the work. The technological scheme of alloy production included joint grinding of the mixture in a planetary mill, consolidation of the blanks, their heating to 1100 0C, hot forging on the arc press and subsequent annealing of hot-forged samples at 1200 0C. According to the results of X-ray analysis of the obtained alloy, it was found that the main phase of the alloy is the BCC phase with the parameter of the cubic lattice a = 0.2868 nm, which is a solid solution based on alloying components of the original charge. The phase composition of the composite also recorded titanium carbide TiC with FCC lattice with the parameter a = 0.4319 nm, which corresponds to a stoichiometric composition of about TiC0.6 and a small amount of FCC phase of iron-chromium carbide (Cr, Fe)23C6 with lattice parameter a = 1.0645 nm. The material has a high hardness (up to 60-61 HRC), which can provide high resistance of this multicomponent alloy.

Формирование структуры и состава кермета TiC/Al при самопроизвольной инфильтрации расплава алюминия в пористый горячий каркас карбида титана, полученный методом СВС

The morphology of structuring and composition forming of the ceramic-metal composite material (cermet) TiC/Al is shown in obtaining it using a new method with spontaneous infiltration of aluminum melt into a porous ceramic frame of titanium carbide TiC synthesized in the combustion mode of the initial mixture of powders (charge) Ti+C, i.e. in the process of self-propagating high-temperature synthesis (SHS).

Effect of the defectiveness of the carbon sublattice on the elastic properties of cubic titanium carbide TiC-=SUB=-y-=/SUB=-

Changes in the elastic constants cij of disordered cubic titanium carbide TiCy with an increasing the defectiveness of the carbon sublattice are estimated for the first time. It was found that the deviation of titanium carbide from the stoichiometric composition TiC1.0 leads to a decrease in the elastic stiffness constants cij of disordered TiCy carbide with a simultaneous increase in elastic anisotropy. The distributions of Young's modulus E and Poisson's ratio μ in the (100) plane and the distributions of the shear modulus G in the (100), (110), and (111) planes have been calculated as functions on the crystallographic direction [hkl] and on the relative carbon content y in TiCy carbide. The lowest values of the shear modulus Ghkl for TiCy are observed in the (111) plane. Keywords: Titanium carbide, Nonstoichiometry, Vacancies, Elastic properties.

Низкоэнергетическая механическая обработка порошка нестехиометрического карбида титана

Introduction. The practical significance of non-stoichiometric titanium carbides TiCх in various fields of technology and in medicine is expanding. In this regard, it is important to investigate both methods of obtaining titanium carbide powder and its properties in a wide range of stoichiometry. One of the effective ways to influence the physical and mechanical properties of powder systems is its mechanical treatment. Under shock-shear action, which is realized during processing in a ball mill, mechanical energy is transferred to the powder system, as a result of which it is ground, centers with increased activity on newly formed surfaces are formed; phase transformations, crystal lattice deformation, amorphization, formation of defects, etc. are possible. The aim of this work is to study the effect of low-energy mechanical treatment in a ball mill on the structure, phase composition and parameters of the fine crystal structure of non-stoichiometric titanium carbide powder obtained by reduction of titanium oxide with carbon and calcium. Materials and methods. Powder of titanium carbide TiC, obtained by calcium carbonization of titanium oxide was investigated. The powder was treated in a drum type ball mill. The structure of the powders before and after treatment was studied using the Philips SEM 515 scanning electron microscope. The specific surface area was determined by the BET method. The phase composition and parameters of the fine crystal structure of powder materials were investigated by X-ray analyzes. Results and discussion. It was established that an increase of the time of mechanical treatment in a ball mill of a non-stoichiometric titanium carbide powder TiC0.7 leads to an increase in the specific surface area of the powder from 0.6 to 3.4 m2 / g, and the average particle size calculated from it decreases from 2 μm to 360 nm. It is shown that in the process of treatment of the non-stoichiometric titanium carbide TiC0.7 powder, its structural phase state changes. Powder particles consist of two structural components with different atomic ratio of carbon to titanium: TiC0.65 and TiC0.48. Mechanical treatment of titanium carbide powder leads to a decrease in the microstresses of the TiCx crystal lattice and the size of coherently diffracting domains (CDD) from 55 to 30 nm for the TiC0.48 phase. For the TiC0.65 phase, with an increase in the duration of mechanical treatment, as well as for TiC0.48, the size of CDD decreases, and the level of microdistortions of the crystal lattice increases. This indicates that in the process of mechanical treatment, not only the grinding of powder particles occurs, but also an increase in its defects.

Influence of nanoparticle additions to the electrolyte on the structure, composition and corrosion resistance of oxide layers formed by PEO on cast Mg alloy

The effect of various nanoparticles (NPs) added to the electrolyte on the composition, structure, and properties of oxide layers formed by plasma electrolytic oxidation (PEO) on a cast magnesium alloy AZ81A was studied in this work. The oxide layers were obtained by alternating adding silicon dioxide SiO2, silicon nitride Si3N4, yttrium oxide Y2O3, tungsten carbide WC, and titanium carbide TiC NPs to the electrolyte. The obtained oxide layers were studied by scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDXMA), X-ray diffraction analysis (XRD), instrumental indentation and potentiodynamic polarization (PDP). The thickness, roughness, microhardness, adhesion and corrosion resistance of the oxide layers were determined. The greatest increase in the oxide layer thickness, in its hardness and corrosion resistance was observed for TiC and WC NPs added to the electrolyte during PEO. The addition of Si3N4 NPs leads to a decrease in the oxide layer thickness and its hardness, while the corrosion resistance is comparable to the one of the uncoated magnesium alloy.

Nanostructured AlNiCoFeCrTi high-entropy coating performed by cold spray

In this work, solid-state mechanical alloying (MA) and cold spraying (CS) processes were applied to fabricate powder AlNiCoFeCrTi high-entropy alloy (HEA) and then to produce HE coatings on steel substrate. Shot-time MA for 3 h has been employed to synthesize nanostructured equiatomic AlNiCoFeCrTi HEA of metastable supersaturated substitutional solid solution with bcc crystal structure. Although alloying is not complete at this shot milling time, it goes to completion during thermal annealing to achieve the alloy formation. XRD study on mechanically alloyed high-entropy AlNiCoFeCrTi alloy after thermal annealing at 1200 °C for 1 h revealed the formation of a three-phase structure consisting of ordered bcc phase with fine precipitates of intermetallic σ-phase (FeCr) and titanium carbide TiC. The powder agglomerates resulted from annealing were grinded in a ball mill for 1 h. Nanostructured disordered bcc solid solution, TiC and σ-phases are noticed after milling. Coatings of 450 μm in mean thickness were deposited by the CS process using an air like a working gas, temperature and pressure of 450 °C and 0.9 MPa, respectively. The experimental results confirm that CS process can be used to produce HE coatings with low porosity. As a low-temperature deposition process, CS completely retained the HEA phase composition and nanostructure in the coating without any phase transformation. The AlFeNiCoCrTi HE coatings exhibit 10.3 ± 0.3 GPa in Vickers hardness.

Dielektrične karakteristike keramičkih kompozitnih materijala sa metalnom matricom na bazi aluminijuma ojačanom titanijum karbidom

The aim of this research work is to study the dielectric and microwave properties of the three ceramic composites Al2O3-TiC, Al2O3-0.3TiC and Al2O3-0.7TiC. The results obtained show that the effective permittivity increases with the increase in the filling rate of titanium carbide TiC inclusions and their contrasts. As for the classical mixing laws, they make it possible to estimate permittivity for low volume fractions and low contrasts. The values of the real part of the complex permittivity decrease with frequency increase in the two bands X and Ku, while the imaginary part is approximately constant in the X band and takes negative values in the Ku band.

Formation of diffusion titanium coatings from liquid metal media solutions on hard alloys WC-Co and TiC-WC-Co

The technology of diffusion titanium coating from the liquid metal media to the carbide-tipped tolls 15%Ti-WC-6%Co and WC-8%Co have described. The thickness of the coating varies depending on the temperature and holding time of diffusion saturation, and ranges from 2,6 to 5,6 μm on alloys of the 15%Ti-WC-6%Co type, from 2 to 5,4 microns on WC-8%Co alloys. It is revealed, that the elemental composition depended of composition of hard alloy. The microhardness of coating on hard alloy 15%Ti-WC-6%Co is 30000 MPa, and for hard alloy WC-8%Co is 24750 MPa. The high microhardness of the coating is provides by its formation on the basis of titanium carbide TiC. It was found that the elemental composition of the coating depends of the composition of the hard alloy to which it is applied. It was found that the surface layers consist of titanium carbide TiC, α-Ti like bind, intermatallide Ti2Co for 15%Ti-WC-6%Co alloy. The WC-8%Co alloy also include tungsten carbide WC.

Self-Propagating High-Temperature Synthesis of (Al–2% Mn)–10% TiC and (Al–5% Cu–2% Mn)–10% TiC Nanostructured Composite Alloys Doped with Manganese Powder

The influence of alloying with powder manganese on the preparation of nanostructured (Al‒2% Mn)–10% TiC and (Al–5% Cu–2% Mn)–10% TiC composite alloys with the application of the self-propagating high-temperature synthesis (SHS) of titanium carbide TiC nanoparticles from the Ti + C charge in a melt of matrix alloys is investigated. Powder metallic manganese in an amount of 2 wt % is preliminarily introduced into Al and Al–5%Cu matrix bases of composite alloys. This makes it possible to increase the ultimate tensile strength of the aluminum base from 81 MPa (for initial aluminum of the A7 brand) to 136 MPa and that of the aluminum–copper base to 169 MPa. It is revealed that, when alloying aluminum only with manganese, the SHS reaction proceeds weakly and incompletely, while the carbide phase size in the (Al‒2% Mn)–10% TiC alloy varies from a nanolevel to several microns. When adding 10% of the Na2TiF6 haloid salt into the SHS charge, the SHS process is intensified, but the resulting alloy contains numerous pores, inclusions of the unreacted charge, and coarse agglomerates of ceramic nanodimensional TiC particles. When using Ti + C and Ti + C + 10% Na2TiF6 SHS charges with coalloying matrix aluminum by copper and manganese, similar results are acquired. The difference is in the larger distribution uniformity of the nanodispersed TiC phase. The best results are attained with a decrease in the Na2TiF6 additive to 5% of the charge weight, which promotes the smoother and complete synthesis of preferentially nanodimensional TiC particles and the formation of the poreless homogeneous microstructure of the (Al–5% Cu–2% Mn)–10% TiC composite alloy with an ultimate tensile strength of 213 MPa and relative elongation of 6.6%.

Безвакуумный метод получения кубического карбида титана в плазме низковольтного дугового разряда постоянного тока

AbstractThe results of a study on the production of cubic titanium carbide in direct-current arc discharge plasma initiated in open air are presented. A feature of the method is its implementation without the use of gas or liquid protective media preventing the oxidation of products and initial reagents with air oxygen. According to the X-ray diffraction data, graphite gC, hexagonal titanium α-Ti, and cubic titanium carbide TiC are identified in the composition of the powder product. The TiC particles are represented by objects with a regular characteristic cut and sizes from units to tens of micrometers.

A Vacuum-Free Method for Producing Cubic Titanium Carbide in the Plasma of Low-Voltage Direct-Current Arc Discharge

The results of a study on the production of cubic titanium carbide in direct-current arc discharge plasma initiated in open air are presented. A feature of the method is its implementation without the use of gas or liquid protective media preventing the oxidation of products and initial reagents with air oxygen. According to the X-ray diffraction data, graphite gC, hexagonal titanium α-Ti, and cubic titanium carbide TiC are identified in the composition of the powder product. The TiC particles are represented by objects with a regular characteristic cut and sizes from units to tens of micrometers.

The Influence of the Synthesis Temperature on Phase Composition and Structure of Tenary Compounds Obtained from the Powder Mixture of the TiH2-Al-C System

This paper presents the results of an investigation of the features of phase and structure formation of a ternary compound during thermal sintering use of compacted TiH2-Al-C powder blends. The thermal sintering was carried out in a vacuum furnace at temperature 1150, 1300, and 1400 0С. The x-ray diffraction pattern and structural analysis show that the main phase after synthesis at 1150 0С is titanium carbide. The ternary Ti2AlC and intermetallic Ti3Al compound were also identified in the phase composition of the alloy. Increasing the sintering temperature to 1300 °C leads to significant increases in the content of Ti2AlC ternary compounds and accordingly decreases the content of titanium carbide TiC. Is propose a modified model thermal synthesis of ternary compounds of the Ti-Al-C system, which includes the melting of aluminum and its interaction with titanium at low-temperature stages of the process, the formation of the Ti3Al intermetallic compound, formation titanium carbide grains as a result of the interaction of the Al4C3 intermediate metastable phase with titanium or Ti3Al intermetallic compound and the synthesis of ternary Ti2AlC and Ti3AlC2 compounds as a result of the interaction of the Ti3Al intermetallic compound with carbon and Ti2AlC with titanium carbide TiC.

Surface Hardening of Hard Tungsten-Carbide Alloys: A Review

Russian and non-Russian research on the surface hardening of hard tungsten-carbide alloys to improve the wear resistance is reviewed. There is great scope for improving the wear resistance and durability of hard-alloy components by surface strengthening on the basis of various coatings, including coatings with 100-nm structural components. On hard tungsten-carbide alloys, the most common coatings consist of titanium carbide TiC and nitride TiN, characterized by high lattice binding energy and high melting point. If such coatings are applied to hard-alloy tools, the frictional coefficient is reduced by a factor of 1.5–2.0 when cutting steel. The use of a TiN + ZrN ion-plasma coating reduces the frictional coefficient by a factor of 5.9. At present, multilayer coatings are widely employed. The most widespread are TiN + TiC and Al2O3 + TiC coatings. Their wear is proportional to the coating thickness. These multilayer coatings still leave room for improvement in the wear resistance of hard alloys. In Russia, the potential of hard alloys with a strength gradient from a ductile and high-strength core to a wear-resistant surface is being explored. At the Research Institute of Refractory Metals and Hard Alloys, a method has been developed for producing alloys with variable cobalt content over the thickness of the cutting insert. That permits change in alloy composition from VK20 to VK2 over the sample thickness. Correspondingly, the wear resistance of the insert’s working section is equivalent to that of VK2 alloy, while the base is able to withstand considerable flexural stress. Recently, cutting tools with a diamond coating on hard alloys have been adopted in practice. To increase the durability of hard-alloy VK inserts, strengthening based on concentrated energy fluxes may be employed. Examples include treatment of hard-alloy surfaces by γ quanta, ion beams, and laser beams, electroexplosive alloying, and electrospark strengthening.

Development and application of laser cladding modeling technique: From coaxial powder feeding to surface deposition and bead formation

A numerical modeling technique is developed for the processes of coaxial laser gas-powder cladding occurring in additive technologies for the manufacture of complex geometry objects. The model is based on a three dimensional (3D) description of mutually related problems of gas dynamics, powder transport, laser heating, and thermal processes in the clad bead and substrate, which are considered without convection in the melt pool. The results of gas-disperse flow modeling with a triple coaxial nozzle are presented. Analysis of bead profiles on a flat substrate with variation in operating parameters is carried out. It is revealed that a self-consistent and practically reasonable model can be obtained when the considered processes are described in а mathematically conjugate 3D formulation. Comparison of the calculated bead profiles and experimental data (for the powder mixture with 16NCD13 steel and titanium carbide TiC) shows a good qualitative and quantitative correlation. In addition, regularities of the modeled repeated beam scanning and production of overlapped profiles of the beads lying beside each other on the flat substrate are discussed.

Effect of Ball Valve Component Materials on Wear

Features of the wear of mating parts of ball valves made of heat-resistant cast alloy ZhS-6U and cermet based on uncoated titanium carbide TiC–ZhS6U and with wear-resistant TiN and Zr–Ti–N–C coatings are studied. It is established that wear-resistant coatings based on cermets prevent the emergence of hard TiC inclusions at the friction surface thereby reducing friction pair component abrasive and mechanical wear and decreasing the overall degree of ball valve wear.