Tungsten Carbide Particles Research Articles

Tribological and mechanical characteristics of AA6082/TiC/WC -based aluminium composites in dry and wet conditions

The tribological and mechanical characteristics of hybrid metal matrix composite on aluminium alloy 6082 reinforced with titanium carbide (TiC) and tungsten carbide (WC) particles was studied for automotive applications. The hybrid composites were fabricated using stir casting techniques by varying TiC and WC particles. Fabricated samples were prepared as per ASTM standard dimensions to conduct mechanical test such as ultimate tensile strength and hardness. The tribological behavior of the hybrid composites was examined using pin on disc tribometer. Distribution of reinforced particles in hybrid composite was examined with scanning electron microscope (SEM) analysis. The tribological characteristics of specific wear rate and coefficient of friction were examined under dry and wet lubricated conditions. Mechanical characteristics and tribological characteristics of the hybrid composites have significantly improved by the presence of reinforced particles (TiC and WC) respectively.

Synthesis and characterization of BaFe12O19-WC catalysts prepared by mechanical milling

Among the magnetic catalysts, barium hexaferrite (BaFe12O19) stands out, mainly due to its capacity to absorb light in the whole visible light range, its magnetic properties, and chemical stability. In this work, the synthesis of mesoporous barium hexaferrite was performed by the chemical co-precipitation method. Then BaFe12O19 particles were subsequently mixed with 1%, 3%, and 5% of tungsten carbide (WC) particles in order to enhance its properties for visible light catalysis. WC powders were prepared by high energy ball milling (HEBM), and its crystallite size was estimated over time from X-ray Diffraction (XRD) measurements. The particle size of the milled WC powders was analyzed using a Laser diffraction analyzer. Besides, Ultraviolet–visible (UV–VIS) spectroscopy was performed to study the light absorption properties of the mixture. In addition, the specific surface area of the samples was measured with a Brunauer-Emmett-Teller Surface Analyzer. Finally, the size and morphology of BaFe12O19-WC mixtures were studied by Scanning Electron Microscopy (SEM). In accordance with the specific surface area measurements, a considerable area increasing up to 13% was observed for the BaFe12O19-WC (5%) sample in comparison to the pure BaFe12O19. On the other hand, the addition of the WC particles slightly increased the bandgap energy by 1.6% in comparison to the pure BaFe12O19. The results indicate that by the incorporation of WC additive, by this simple and inexpensive method, the surface area of the BaFe12O19 can be modified to enhance its properties for its use in visible light catalysis applications.

Thermodynamic analysis of the interface reaction and thermal stress of WCp/Fe composites

One of the key issues for composites is the formation mechanism and stability of the interface. Experimental technology and first-principles calculations with quasiharmonic approach considering the phonon and thermal electronic contribution are adopted to clarify the thermodynamics and thermal stress of the interface of tungsten carbide particle reinforced iron matrix (WCP/Fe) composites under finite temperature. The most favorable formation path of Fe3W3C at the interface is 3Fe+2WC + W2C→Fe3W3C+2C + W. For WCP/Fe and WCP/Co composites, the thermal stress of Co3W3C is smaller than Fe3W3C as the transition phase of the interface, and Fe is less suitable to be applied as the matrix of composites than Co. Our research provides significant guidance to improve the interfacial strength and stability of WCP/Fe composites.

Mechanical and Tribological Behavior of Mg-Matrix Composites Manufactured by Stir Casting

In the recent decades, magnesium matrix composites present a plenty of applications in automotive, marine and aerospace industries. In this work, AZ31B is selected as Mg matrix material and hard Tungsten carbide (WC) particles as reinforcement material. Mg/WC composites are reinforced with different weight proportions (0, 5, 10 and 15% wt.) using stir casting method. The worn surface of manufactured Mg/WC composites and base Mg material were examined by scanning electron microscope (SEM). The wear test results denote that AZ31B/15% wt. WC composites have excellent tribological behaviour when compared to the base magnesium matrix AZ31B alloy. The yield tensile strength, flexural strength, ultimate tensile strength and micro-hardness of the manufactured composites are improved by increasing the WC content. Further, SEM analysis revealed the homogeneous distribution of WC particles throughout the Mg matrix.

On the influence of two coexisting species of susceptibility-producing structures on the R2∗ relaxation rate

PurposeTissue microstructure can influence quantitative magnetic resonance imaging such as relaxation rate measurements. Consequently, relaxation rate mapping can provide useful information on tissue microstructure. In this work, the theory on relaxation mechanisms of the change of the relaxation rate ∆R2⁎ in the presence of spherical susceptibility sources in a spin bearing medium is validated in simulations and phantom experiments for the coexistence of two species of susceptibility sources. MethodsThe influence of coexisting spherical perturbers with magnetic susceptibilitys of different signs was evaluated in Monte Carlo simulations including diffusion effects in the surrounding medium. Simulations were compared with relaxometry measurements at 1.5 Tesla and at 3 Tesla. The phantoms used to validate the simulations were built from agarose gel containing calcium carbonate and tungsten carbide particles of different size and concentration. ResultsThe Monte Carlo simulations showed, that the change in relaxation rate only depends on the overall amount of susceptibility producing structures in the simulation volume and no difference was found, if mixtures of positive and negative particles were simulated. Phantom measurements within the static dephasing regime showed linear additivity of the effects from positive and negative susceptibility sources that were present within the same voxel. ConclusionsIn summary, both the simulations and the phantom measurements showed that changes in the relaxation rate ΔR2⁎ add up linearly for spherical particles with different susceptibilities within the same voxel if the conditions for the static dephasing regime are fulfilled. If particles with different susceptibilities have both different sizes and violate the conditions of the static dephasing regime, effects on relaxation rates might no longer be linear.

Effect of the Initial Temperature on the Penetration of Tungsten-Based Porous Alloy Strikers with a Hardening Filler into a Steel Obstacle

We propose a series of experiments aimed at analysis of peculiarities and revealing general regularities in the penetrability of strikers made of a composite material based on tungsten + nickel + iron + cobalt alloy with an admixture of highly rigid refractory titanium–tungsten carbide particles in various initial conditions. In particular, we have analyzed the effect of the initial temperature of the striker in the interval from –50 to 50°C on the penetration into a steel obstacle experimentally and by calculations. It is found that the initial temperature of the striker does not noticeably affect the penetration depth in the obstacle at impact velocities up to 2500 m/s. The penetrability is found to be 20% higher than that for a monolithic massive analog made of VNZh-90 alloy.

Capturing Marangoni flow via synchrotron imaging of selective laser melting

Marangoni flow has a substantial influence on the quality of components fabricated via laser powder bed fusion (LPBF). However, Marangoni flow in melt pools is rarely quantified due to the opacity of liquid metals and the necessity for in situ evaluation. Here we report the findings of high-temporal-resolution synchrotron x-ray radiography experiments tracking the flow in the melt-pool. Dense, highly attenuating tungsten carbide particles are seeded within an elemental powder blend of aluminium and copper of varying composition. Due to the extremely high temporal resolution of greater than 50 kfps at the 31-ID-B beamline at the Advanced Photon Source, USA, we can track the position of tracer particles from frame to frame. This data provides valuable process guidance for optimising mixing and informs the development and validation of multiphysics models.

Studying the Effect of Fine Particles of Tungsten Carbide on the Macro-Structure, Hardness and Microhardness of Gradient Steel Billets

Creating a gradient of properties in a single material is challenging for scientists and engineers. For this purpose, such methods are used as: welding of steels of different chemical compositions, joint rolling of steel sheets, sealing and surfacing of various kinds. All of these methods have a big disadvantage: under load, the material is destroyed in the weakest place - the place where the layers join. In this article, the authors proposed to obtain a gradient of properties in steel castings due to the introduction of dispersed particles of tungsten carbide into the crystallizing melt during centrifugal casting. The particles introduced serve as crystallization centers, accelerate the crystallization process and increase certain types of mechanical properties (hardness, microhardness, tensile strength). In addition, the particles of tungsten carbide have high hardness; therefore, in the structure of the workpieces they serve as reinforcing elements that strengthen the structure. The uneven distribution of particles in the preform being formed is possible for two reasons: tungsten carbide has a density greater than the melt, and besides, centrifugal force acts on them. The article describes the experiment and its results on the production of metal preforms with a gradient of properties. The introduced particles significantly influenced the macro-structure of the prepared castings. The article also presents the results of a study of the effect of particles on the hardness and micro-hardness of the resulting blanks.

Laser-Induced Breakdown Spectrometry for Analyzing the Composition of the Products during Coaxial Laser Cladding

We demonstrate the possibility of the quantitative multielement analysis of a composite wear-resistant coating (tungsten carbide particles in chromium–nickel matrix) during its synthesis by coaxial laser cladding. The developed probe for the laser-induced breakdown spectrometry (LIBS) was used for the online analysis of the concentration of carbon, tungsten, and nickel in the process of applying a wear-resistant coating. The results of online LIBS measurements agreed closely with the results of the offline analyses using conventional methods such as X-ray fluorescence spectrometry, X-ray spectral electron probe microanalysis, and the combustion infrared absorption method using a LECO gas analyzer.

Aluminium Metal Matrix Composition with Reinforcement Particles of Tungsten Carbide and Graphite

Aluminium Metal Matrix composition were used in application of the aerospace and automobiles because of its strength and stiffness. Although tribological characteristics of the materials like wear resistance is low. Many research has been carried out in the particle reinforcement with the Aluminium Metal Matrix. In this paper, the several reinforced particles with the aluminium matrix were reviewed. The reinforced materials like Tungsten carbide, graphite or hybrid reinforced materials were analyzed. The stir casting process is the common technique to fabricate these materials. The reinforcement of graphite particles in aluminium materials were shows the considerable mechanical properties.

Fabrication of robust tungsten carbide particles reinforced Co[sbnd]Ni super-hydrophobic composite coating by electrochemical deposition

Nowadays, the practical application of the super-hydrophobic surfaces is limited by their mechanical durability. In this work, robust super-hydrophobic cobalt-nickel coatings reinforced by micro-nano tungsten carbide (WC) particles were achieved on carbon steel substrate by electrochemical deposition from the mixed solution. The effect of WC particles content on the surface morphology, wetting properties and the corrosion protection performance of the composite coatings were investigated. The linear abrasion test indicated that the as-prepared super-hydrophobic CoNi/WC composite coating with 9.8 wt% WC content, displayed excellent wear resistance with super-hydrophobic property for abrasion distance up to 34 m. Furthermore, the super-hydrophobic CoNi/WC coating with robust mechanical durability can be a promising alternative technique for corrosion protection.

A study of Cr3C2-based HVOF- and HVAF-sprayed coatings: Abrasion, dry particle erosion and cavitation erosion resistance

Material and spray process selection are the key factors in the tailoring of thermal sprayed coatings for demanding industrial applications. In this study, four commercial Cr3C2-based feedstock materials were sprayed with gas-fuelled high-velocity oxygen-fuel (HVOF) and modern high-velocity air-fuel (HVAF) spray processes. Two materials with standard Cr3C2–25NiCr composition (porous and dense), a Cr3C2–50NiCrMoNb and Cr3C2–37WC–18NiCoCr materials were sprayed in addition to the reference WC-10Co4Cr material. The Cr3C2–50NiCrMoNb had a higher content of the Ni-based metal matrix compared to standard Cr3C2–25NiCr composition for added corrosion resistance, while the Cr3C2–37WC–18NiCoCr material contained additional tungsten carbide (WC) particles to improve the wear resistance. In abrasion and dry particle erosion, the Cr3C2–50NiCrMoNb coatings showed a higher degree of plastic deformation and increased material loss, whereas the Cr3C2–37WC–18NiCoCr coating had wear resistance between the standard Cr3C2–25NiCr and reference WC-10Co4Cr coatings. In cavitation erosion, the lower carbide content of Cr3C2–50NiCrMoNb coatings turned out to improve the resistance against fatigue wear due to higher fracture toughness. Overall, the HVAF sprayed coatings had higher elastic modulus, higher fracture toughness, equal or higher abrasion and erosion resistance, and higher cavitation erosion resistance compared to the HVOF sprayed counterparts.

Production, Bonding and Application of Metal Matrix Composite Hot Forging Tool Components

Metal matrix composite materials are of high interest for their increased stiffness, strength or wear resistance. Wear resistant composites contain hard ceramic particles to reduce microcutting and grooving of the metal matrix surface. In this paper, a gas atomised hot work tool steel X40CrMoV5-1 (1.2344/AISI H13) was combined with fused tungsten carbide (FTC) particles in order to create forging tools with increased abrasive wear resistance. For that purpose, tool components were manufactured by sinter-forging of stacked powder layers to build up a graded hard phase concentration of up to 10 vol.-%. Subsequently, sinter-forged specimens were combined with basic hot work tool steel components and joined by diffusion bonding to assemble the complete tool. In order to evaluate their performance, the tools were examined in a hot backward can extrusion process of low-alloyed steel. Optical geometry measurements, light microscopy and scanning electron microscopy of the worn tool radii indicated a significant decrease in abrasive wear when using FTC-reinforced tools rather than conventional hardened tool steel.

Влияние начальной температуры на процесс проникания ударников из пористого сплава на основе вольфрама с упрочняющим наполнителем в стальную преграду

A researches series aimed at studying the features and revealing the general laws of penetration of impactors made of composite material based on a porous tungsten + nickel + iron + cobalt alloy with the addition of highly hard refractory particles of tungsten carbide under various initial conditions was continued. In particular, the effect of the initial impactor temperature in the range from −50 to 50 °C on the process of penetration into the steel shield by the experimental and computational methods was studied. The absence of appreciable effect initial impactor temperature in this range for the penetration depth into the shield at impact velocities of 2500 m/s was revealed. The penetration is exceeded by 20% compared with the monolithic mass-size analog of the WNiFe-90 alloy.

Increasing the wear resistance of steel bandage by surface laser modification with tungsten carbide particles

Currently, the wheel flange limiting wear is the main reason of the railroad wheels trueing. In order to enhance the wear resistance of the wheels to the required level, composition of their surface shall be changed, which is proposed to do by the method of laser surface modification introducing spherical particles of tungsten monocarbide with diameter from 50 to 150 μm. It was found out that introduction of the said particles into steel, which composition corresponds to grade 2 as per GOST 398-2010, results in reduction of microhardness of matrix metal formed on the composite layer surface as long as the content of tungsten monocarbide particles is increased. This phenomenon shall be probably connected with the change of chemical composition and stress-strain state of metal. Examination of wear resistance using roller samples demonstrated that growth of the volumetric fraction of reinforcing particles significantly increases the wear resistance. Laser heat processing of the surface without introducing the particles results in the wear resistance increase too. Wear and tear of the counter rollers cut from the rail operated in pair with the reinforced rollers cut from the tread band is less than in the pair with untreated rollers. Introduction of reinforcing particles is much more important than matrix hardening for increasing the wear resistance. It is demonstrated that cross-crack defects can be formed in modified layers, which quantity depends on the volumetric fraction of reinforcing particles. When content of tungsten monocarbide is less than 10%, cracks are not observed. According to the totality of properties, the best content of reinforcing particles shall amount from 8 to 10% of the volume.

Thermomechanical Wear Testing of Metal Matrix Composite Cladding for Potential Application in Hot Rolling Mills

Laser metal deposition (LMD) is utilized to clad the surface of a miniaturized test roll (Ø 40 mm) of tool steel. The cladding consists of two layers: a nickel alloy as intermediate layer deposited onto the surface of the steel substrate, and a metal matrix composite (MMC) as top layer consisting of spherical tungsten carbide particles embedded into the nickel alloy matrix. The thermomechanical wear behavior of the cladding is investigated on a test rig, where the test roll is pressed against an inductively heated load roll. Multiple test runs up to several hours simulating industrial loading conditions are performed. The presented testing procedure enables predicting the time‐dependent abrasive wear behavior of the cladding, in particular for hot rolling mill applications. After testing for 8 h at temperature of 650 °C and at contact pressure of approximately 1 GPa, the maximum depth of the wear mark is about 0.12 mm. Partial cracking, debonding and dissolution of the tungsten carbide particles, as well as formation of iron and chromium oxides at the surface of the wear marks occur. However, as low abrasive wear is observed, the investigated MMC may potentially be applicable for cladding rolls in steel hot rolling mills.

Preparation of spherical WC–W2C composite powder via noble metal-free catalytic electroless nickel plating for selective laser melting

In this present work, Nickel-coated tungsten carbide powder was prepared by high concentration electroless nickel plating without noble metal catalysis and the WC/W2C based composites were successfully prepared by Selective laser melting (SLM). The Ni layers covering on tungsten carbide particles were controlled by the reagent type of complexing agent, stabilizing agent, and surfactant. When Trisodium citrate is used as a complexing agent, it has a well complexing effect on metal ions, but the other complexing agent is poor effect. Compared with ordinary electroless plating, it is not suitable to use stabilizers for high concentration electroless plating. When Polyvinyl Pyrrolidone is used as surfactant, a dense coating layer can be obtained and the coating surface is relatively smooth. Nickel-plated cast tungsten carbide powder as the main raw material, SLM prepared tungsten carbide-based composite materials with uniform microstructure distribution and high relative density. The hardness of the composite increases as the energy density increases. When the energy density is 1000 J m−1, the density can reach 13.183 g cm−3 and the relative density is 96.8%, which will help to pave the way for the application of ceramic composites in SLM.

Influence of refractory nanosized particles of tungsten carbide and titanium on the structure and properties of the weld metal

The paper considers the influence of nanosized particles of tungsten and titanium carbides on the structure and properties of the weld metal of welded joints made by automatic submerged-arc automatic arc welding. To add them into the weld pool, an alloying composition was used in the form of composite granules based on nickel powder (PNE-1 as per GOST 9722). The prospects of using nanosized tungsten carbide particles for modifying the weld metal with the aim to increase the values of impact strength were shown. However, titanium carbide in the same conditions leads to a decrease in the average value of impact strength, despite the modifying effect of its use.

Erosion wear analysis of HVOF coated Colmonoy-88 and Stellite-6 micron layers on pump impeller steel by using the Taguchi's approach

PurposeThis paper aims to depict the erosion performance of two HVOF-coated micron layers (Colmonoy-88 and Stellite-6) on pump impeller steel (SS-410) by using Taguchi's method. Taguchi's array (L16) was used to optimize the erosion wear (in terms of weight loss) by using four influencing parameters such as rotational speed, solid concentration, average particle size and time which were varied at four different levels.Design/methodology/approachThe experiments were carried out by using a Ducom slurry tester with rotational speed in the range of 750-1,500 rpm, solid concentration of 35-65 per cent by weight, time period of 75-210 min and average particle sizes in the range of < 53 to 250 µm. Bottom Ash with a nominal size range of < 53 to 250 µm was used as erodent. The process parameters were optimized by using Taguchi's method. The ANOVA method was used to validate the results given by Taguchi's method.FindingsThe results revealed that the presence of both carbides and borides and the additional presence of Cr in Colmonoy-88 coating enhancing the slurry erosion resistance of Colmonoy-88 coating. Moreover, the chromium and tungsten carbide particles help in increasing the bond strength between the coating and the substrate material. Further, it was also found that the time was the most dominant factor as compared to other factors.Originality/valueThe very less work has been reported on optimization of erosion wear response of Colmonoy-88 and Stellite-6 coatings by using different design of experiment techniques. Further, the erosion wear mechanism of both coatings has been studied by using image j analysis software.

In situ TEM observation of sintered Ag die-attach layer with added tungsten carbide particles while heating to high temperature

We carried out in situ transmission electron microscopy (TEM) on the microstructural change of a sintered Ag die-attach layer heated to 600 °C. It was found that the addition of 2 wt% tungsten carbide (WC) particles to the sintered Ag layer significantly suppressed the microporous structure growth at elevated temperature. In the case of a pure Ag layer without anything added, microporous structure growth started from 450 °C. However, microporous structure growth was hardly observed in the sintered Ag layer with WC added up to 600 °C.