Tungsten Carbide Research Articles

Comparison of pain and efficacy of caries removal using tungsten carbide bur versus chemomechanical agent (Brix Gel): A randomized controlled trial.

Objective: To compare the pain response and efficacy of caries removal using tungsten carbide burs with that of using Brix Gel as a chemomechanical caries removal agent. Study Design: Randomized Controlled Trial. Setting: Department of Operative Dentistry, PIMS, Islamabad. Period: November 2023 to April 2024. Methods: Conducted on 40 participants were selected using a non-probability technique. Participants aged 12 to 65 years with open occlusal carious lesions involving dentin were included. Patients with symptoms of pulpitis, caries affecting maxillary or mandibular anterior teeth, severe systemic illnesses, allergies, sensitivities, or pregnancy/lactation were excluded. Caries removal methods were randomly assigned. Pain levels were assessed using a Visual Analog Scale (VAS), and caries removal efficacy was evaluated. Statistical analysis was done using chi-square and independent samples t test. Results: Among the 40 participants, 47.50% were female, and the mean age was 36.30±15.57 years. Mandibular molars were the most commonly affected teeth (n=24, 60%). No significant difference in age or gender distribution was observed between the two groups. The chemomechanical method resulted in significantly lower pain scores compared to carbide bur (2.59 ± 1.34 vs. 4.44 ± 1.61, p < 0.001). Pain severity also differed significantly between groups, with more mild pain reported in the chemomechanical group (80.00% vs. 5.00%, p < 0.001). However, caries removal efficacy did not significantly differ between the two methods (p = 0.48). Conclusion: Chemomechanical caries removal using Brix Gel demonstrated superior pain management compared to carbide bur. While both methods showed similar efficacy in caries removal, the chemomechanical approach may offer better patient comfort during the procedure.

Study on process optimization of electroless Ni-P plating on binderless WC

Abstract In the field of Precision Glass Molding (PGM), binderless tungsten carbide (WC) is a pivotal material for molds, despite its high processing costs and complexities. Nickel-phosphorus (Ni-P) alloys also exhibit superior performance at elevated temperatures. The innovation of Ni-P/WC composite molds addresses the issue of the poor machinability of WC. This research delves into the influence of the activating solution’s concentration on the surface activation energy of WC, the quality of plating, and the deposition rate during the electroless Ni-P plating process. Additionally, the study scrutinizes how the pH level of the plating solution impacts the quality of Ni-P, the rate of deposition, and the phosphorus content. These investigations have led to the realization of an efficient and high-quality Ni-P plating process for WC.

Ultrahigh Pressure Generation at High Temperatures in a Walker-Type Large-Volume Press and Multiple Applications

Ultrahigh pressure generation at high temperatures is technologically challenging for large sample volumes. In this study, we successfully generated pressures of 37.3–40.4 GPa at 1900–2100 K in a Walker-type large-volume press (LVP). Expansion of the pressure range at high temperatures was achieved by adapting newly designed ZK01F tungsten carbide (WC) anvils with tapered surfaces and using cell assemblies with an ∼1 mm3 sample volume and hard materials, as well as by applying certain adjustments to the apparatus. The pressure efficiencies of the different types of WC anvils and cell assemblies were also studied. Using the above-mentioned techniques, we successfully synthesized and characterized bulk samples of nearly pure sp3-hybridized ultrahard amorphous carbon, core–shell nanocrystals with high Néel temperatures, as well as large-sized single crystals of lower-mantle minerals. The developed LVP techniques presented here could enable the exploration of the chemical and physical properties of novel materials and Earth’s interior.

Synergistic heterostructural interface of CoP and WC for high-performance wide pH-universal hydrogen evolution electrocatalysis

The development of cost-effective catalysts with high activity and stability over a wide pH range is urgent, but there are great challenges in the selection and design of catalyst materials. In this work, cobalt phosphide nanoparticles were modified onto tungsten carbide nanowire arrays (CoP@WC/CC) on carbon cloth substrate by a two-step method. The construction of CoP@WC heterostructure results in the downward shift of the d-band center, which optimizes the adsorption energy of catalyst and reaction intermediates. Meanwhile, the synergistic effect of CoP and WC contributes to the alkaline HER kinetic process. In addition, binder-free self-supporting nanoarray have excellent electrical conductivity, large specific surface area and strong structure, which is conducive to charge/matter exchange and catalyst stability. The results show that CoP@WC/CC can effectively drive HER over a wide pH range and exhibit better catalytic performance than the single component control sample. In 0.5 M H2SO4 and 1 M KOH, CoP@WC/CC can drive the current density of 10 mA cm−2 with only 52 and 70 mV, while showing excellent stability without obvious performance degradation during 100 h of constant current test. A proton exchange membrane water electrolysis (PEMWE) using CoP@WC/CC catalyst operates stably for 200,000 s at 30 mA cm−2. This study provides a new reference for the design and development of high efficiency, low cost and wide pH-universal hydrogen evolution electrocatalysts.

TRIBOLOGICAL INVESTIGATION OF TUNGSTEN CARBIDE AND HARD CHROME COATINGS ON EN19 FOR COLD ROLLING APPLICATION

In the heavy sheet metal industry, rolls are generally made up of EN19. To enhance the life of the cold rolling mills it can be coated. This paper presents an experimental study to check the effect of alloy coatings such as Hard Chrome and Tungsten carbide on wear resistance and other characteristics of roller base materials EN19 which is used in rolling process of heavy metal industry. In this paper a comparative tribological study of Hard Chrome, Tungsten carbide, EN19 through hardness testing, surface roughness analysis, SEM, and EDS, XRD, sliding wear experiments and statistical study through Design of Experiment has been performed to find out the best material which can increase the life of rolls. From the experiments carried out it has been found that hardchrome has 15.19 times the longevity of the substrate EN19. Tungsten carbide has 19 times the life of EN19 and 1.25 times the life of hardchrome. Tungsten carbide coating gives more hardness and wear resistance than the Hard Chrome and EN19 base material of the roll. Thus, using Tungsten carbide coating on EN19 rolls will improve the life and enhance the longevity of the roll used in cold rolling process in heavy steel industry.

Thermodynamic aspects of WO3 tungsten oxide reduction by carbon, silicon, aluminum and titanium

The development and research of new materials for machine parts of the mining and metallurgical complex by the method of surfacing with flux cored wire has a lot of attention nowadays. Flux cored wires are widely used for surfacing of steels with high wear resistance, in which reduced tungsten in the form of ferroalloys, ligatures and metal powder of various degrees of purity are used as fillers. However, due to the scarcity and high cost of tungsten, its rational use is an urgent task. For practical application, the technology of surfacing with tungsten-containing flux cored wire is of interest; using it the maximum extraction of tungsten into the deposited layer is achieved due to reduction processes in the arc. In order to increase the beneficial use of tungsten, the technologies of indirect alloying with tungsten during surfacing under the flux of flux cored wires, in which tungsten oxide is used as a filler on the one hand, and reducing agent – on the other, deserve consideration. It can be expected that during arc discharge, tungsten and (or) chemical compounds of tungsten with reducing agents can be formed during the surfacing process. This paper presents the results of a comparative analysis of the thermodynamic processes of tungsten oxide reduction by carbon, silicon, aluminum and titanium during arc discharge occurring during surfacing with flux cored wires under a layer of flux. The thermodynamic analysis of 41 reactions in standard states showed that the presence of reducing agents (carbon, silicon, aluminum, titanium) in the flux cored wire used for surfacing will contribute to the formation of silicides and tungsten carbides, and, possibly, tungsten itself. It was determined that the best state for the participation of tungsten oxide in reactions in the arc is WO3(g) gaseous state.

Effect of adhesives and mechanical surface treatments on the hard relining of CAD-CAM denture bases.

The aim of this study was to evaluate the impact of mechanical roughening, adhesive applications, and aging on the bonding between CAD-CAM denture base materials with distinct chemical contents and hard relining material. A total of 300 denture base specimens were produced by additive, subtractive, and conventional heat-polymerization techniques (N=100). The specimens have been classified into five subgroups based on the particular surface treatments administered (n=20): (1) Hard relining material's adhesive application (control); (2) Tungsten carbide bur application for 1min, and hard reline material's adhesive application; (3) Airborne-particle abrasion (APA) with 110 μm Al2O3, and hard reline material's adhesive application; (4) Scotchbond Universal application; and (5) Visio.link application. Representative specimens from each subgroup were examined under a Scanning Electron Microscope (SEM). Subsequently, self-cure hard relining material was condensed in the center of the specimens. Half of the specimens were thermally aged with 5000 cycles at 5°C-55°C. The shear bond strength (SBS) test was performed, and failure loads were recorded. The data was evaluated by Robust ANOVA and Bonferroni test (p<0.05). No statistically significant difference was obtained between the production techniques (p = 0.051). The lowest SBS was observed in the control group among surface treatments, while mechanical surface treatments and universal adhesive showed the highest SBS for both aged and non-aged groups. Aging caused a significant decrease for all test groups (p=0.001). Mechanical surface treatments and universal adhesive applications are more effective for maintaining adhesion across all production techniques.

Optimization of multiple responses in the laser cladding process parameters

ABSTRACT An orthogonal test method was used to optimize parameters for Ni60A-25% tungsten carbide (WC) laser cladding layers. Meanwhile, the tensile properties of the optimized laser cladding layer are explored. A multi-factor analysis of variance (ANOVA) was conducted to examine the effect of factors (laser power-A, scanning speed-B, powdering rate-C, and spot diameter-D) and interactions on responding variable. The results showed that the interaction of scanning speed and powdering rate with spot diameter has a more pronounced impact on the dilution rate compared to a single factor. Based on the ANOVA of the dilution rate, the optimal combination of process parameters was A3C2B1D3. Furthermore, the optimal combination of process parameters was C3B2D3A3 for the effective area. The results showed that the yield strength of the specimens was 512.3 MPa and 509.7 MPa, and the tensile strength was 646.3 MPa and 605.7 MPa for process parameters I and II, respectively.

Multi-criteria decision making for better quality indicators in µ-EDM using TiN-coated WC electrode

ABSTRACT It is highly essential to enhance the micro EDM process while machining titanium specimens. The utilization of coated electrode and adaptation of optimization algorithms in the process can enhance the material removal mechanism. In the present work, an attempt was made to find the influence of TiN coated tungsten carbide electrode in micro EDM process while machining titanium alloy specimens. It was also attempted to adopt DEAR-based optimization in the process. The TiN coating can produce lower TWR with better surface quality than uncoated tungsten carbide electrode. The capacitance has higher influential nature in µ-EDM since it controls the charging and discharging process during the spark formation across discharge gap. It was found that voltage (Level 3), capacitance (Level 3), and the tool rotation (Level 2) can create better quality measures under the prediction error of 2.3%. The optimal combination can enhance the machining accuracy with tiny craters formation.

Obtaining of WC–Co- and WC–TiC–Co-Based Ultradispersive Alloys Modified with B&lt;sub&gt;4&lt;/sub&gt;C–TiB&lt;sub&gt;2&lt;/sub&gt; Quasieutetic

Tungsten carbide WC-based materials characterized by high hardness and wear resistance have long been widely used in manufacturing cutting and mining tools. They are alloyed or modified with different ceramic phases to improve operational characteristics further. There are obtained the hard tungsten carbide–cobalt WC–Co and tungsten carbide–titanium carbide–cobalt WC–TiC–Co metal-ceramic alloys ultradispersed powders modified with quasieutectic ceramic alloy B&lt;sub&gt;4&lt;/sub&gt;C–30wt.%TiB&lt;sub&gt;2&lt;/sub&gt; and complex samples compacted from them. The quasieutectic alloy used as a modifier has almost as high hardness as pure boron carbide. Still, it is characterized by higher electrical and thermal conductivities of several orders of magnitude. Two groups of hard alloys modified with B&lt;sub&gt;4&lt;/sub&gt;C–30wt.%TiB&lt;sub&gt;2&lt;/sub&gt; were studied: ВK8 grade WC–Co and T30K4 and T15K6 grades WC–TiC–Co. Metal-ceramic composite powders of different concentrations are obtained by chemical synthesis and mechanical dispersion in an attritor. The particle size of chemically synthesized composite powders is ≤0.3 μm, and those obtained by mechanical dispersion are ≤0.8 μm. SPS (Spark-Plasma Sintering) and HTS (High-Temperature Sintering) methods compact these powder materials. Phase composition of the obtained materials, distribution of chemical elements in them, and structural features are investigated by the XRD (X-Ray Diffraction) method and EDX (Energy Dispersive (micro)X-ray) spectrometry and optical and electron microscopies, respectively. Key physical-mechanical characteristics of the received samples, such as hardness, microhardness, and bending strength, are studied. Ultradispersed (≤0.8 μm) metal-ceramic alloys of the WC–Co–B&lt;sub&gt;4&lt;/sub&gt;C–TiB&lt;sub&gt;2&lt;/sub&gt; system with interesting characteristics have been obtained using the WC–Co hard alloy of BK8 grade as the matrix. A SPS-compacted sample's hardness, microhardness, and bending strength are 93.0 HRA, 3350 kgf/mm&lt;sup&gt;2&lt;/sup&gt;, and 100 kgf/mm&lt;sup&gt;2&lt;/sup&gt;, respectively. Among the WC–TiC–Co system materials, the Т15K6 grade-based hard alloy modified with 15wt.%(B&lt;sub&gt;4&lt;/sub&gt;C–30wt.%TiB&lt;sub&gt;2&lt;/sub&gt;) has the best characteristics with hardness, microhardness, and bending strength of 91.5 HRA, 2900, and 117 kgf/mm&lt;sup&gt;2&lt;/sup&gt;, respectively. A preliminary study of the problem of environmentally safe utilization of tungsten-containing scrap and tungsten waste is also carried out as part of the work. In particular, the tungsten heater waste is treated in hydrogen peroxide, and by adding specific liquid components to the tungsten-containing proper solution in a single utilization–synthesis cycle, the target product – ultradispersed WC–Co hard alloy is obtained.

Structural study of carbon deficient tungsten carbide nanoparticles prepared by different carbon sources

Structural study of carbon deficient tungsten carbide nanoparticles prepared by different carbon sources

Characterization of an additively manufactured coating using an upsetting test with miniaturized cylindrical specimen

In order to reduce CO2 emissions in production industry, the combination of several manufacturing processes is coming to the fore. One example is the combination of metal additive manufacturing with the forming technology, whereby the advantages of both process technologies can be used. The process combination can be applied to produce hybrid barrel sleeves, for example. Using a laser-based directed energy deposition (DED-LB/M), a circular coating is first applied to a blank, which is then deep-drawn in a second step. The additive layer serves as a wear-resistant coating. One way to increase process understanding for this process combination is numerical simulation. An important part of setting up the simulation model is characterizing the material in terms of its mechanical behavior. In order to avoid long building times, small sample geometries are suitable for characterizing the additive material. In the context of the paper, the upsetting test is therefore carried out with miniaturized specimens, whereby not only the base material Bainidur AM but also the addition of tungsten carbide microparticles and carbon nanoparticles is investigated. The in-situ modification of the material significantly increases the yield strength, but at the same time reduces the ductility. The microhardness of the material is also increased by the addition of carbon or tungsten carbide.

Optimization of Machining Process on Coated Tungsten Carbide Electrode Tool and Titanium Alloy Workpiece Using EDM: A Critical Review

Commercial applications for Ti 6Al 4V, an alloy composed of titanium, aluminium, and vanadium, are possible. The features of titanium alloy include: Lightweight, non-magnetic, high melting point, outstanding fatigue strength, superior specific strength, great corrosion resistance, and biocompatibility. Reviewing the electro-discharge machining of titanium alloy (Ti 6Al 4V) as a workpiece, silicon carbide particle combined with EDM oil, and coated tungsten carbide electrode, this research examines this process. Dielectric fluid's impact on microhardness, surface finishing, TWR, and MRR. MRR is raised by silicon particles and coated tungsten carbide electrodes with EDM fluid. According to the study, the most important input parameters for determining TWR, MRR, surface finishing, and micro-hardness are voltage, current, pulse on time (Tonne), and pulse off time (Toff).

Investigating micro-EDM machinability of Ti-35Nb-7Zr-5Ta (TNZT) alloy

ABSTRACT Titanium and its new-generation alloys are widely employed in high-end applications due to their special properties. Modern industries frequently use micro – Electro Discharge Machining (μ-EDM), a non-conventional machining technique that is especially useful for processing hard to machine materials like titanium alloys. μ-EDM can produce intricate shapes with excellent dimensional precision. The main emphasis of this work is an experimental analysis of the μ-EDM of TNZT alloy (Ti-35Nb-7Zr-5Ta) employing a tungsten carbide (WC) electrode. The results showed that with the increase in capacitance (C) 10nF to 100nF at Voltage (V) 80 V, the machining performance parameters such as material removal rate (MRR), overcut (OC), crater area, surface microhardness, and surface roughness increase by 6.38, 1.52, 4.66, 1.07, and 3.29 times, respectively. However, the circularity error of the µ-hole increases by 1.81 times. This study intends to show how the two key machining factors (C & V) influence significant machining performance parameters.

Analyzing point defect polarization in tungsten and tungsten carbide under high gamma irradiation for radiation shielding applications

In this study, polycrystalline tungsten and tungsten carbide samples were irradiated with gamma rays at energies of 1.17 MeV and 1.33 MeV, respectively. The irradiation was performed using an “MRX-γ-25 M” radiation camera with an activity of approximately 6.54 Gy/s. Doppler positron spectroscopy (DPS) and positron lifetime spectroscopy (PALS) were utilized to investigate the mechanisms of defect formation in the polycrystalline structure of tungsten samples at different doses of gamma irradiation. In the initial tungsten sample, a significant number of free monovacancy (1 V) clusters were present. An increase in the positron lifetime component τ1 was observed with increasing gamma irradiation, accompanied by a decrease in its intensity. The τ2 value (218 ± 2 ps) suggests the presence of divacancies with a considerable intensity (∼20%). As the gamma dose accumulated, a dynamic evolution of structural defects was evident. The tungsten carbide (WC) samples displayed greater plasticity in response to increasing gamma irradiation doses. Changes in the void volume ratio within the samples were recorded as the gamma dose increased, and movement of these voids towards the surface was observed. Additionally, the operational limits of gamma-irradiated tungsten were assessed, determining a functional threshold of up to 3.378 MGy. This study provides valuable insights into the defect dynamics and structural changes in tungsten and tungsten carbide under gamma irradiation, contributing to the understanding of their behavior in radiation environments.

Evaluating the effectiveness of color changing adhesives versus ultraviolet absorbent dye additive adhesives in the removal of adhesive remnants after orthodontic debonding

The fixed orthodontic treatment initiates with bonding and ends up with debonding of brackets which alters the enamel surface. The adhesive remnants present on the enamel surface after debonding are removed with the help of various aids but alters the enamel surface to an extent and there is no alternative material or instrument for removing the adhesives. The aim of the study was to compare the effectiveness of color changing orthodontic bonding adhesives versus ultraviolet absorbent dye additive orthodontic bonding adhesives in the removal of adhesive remnants after orthodontic debonding.: 40 extracted human premolars were procured and metal brackets were bonded to the buccal surface with Group 1 – Enlight, Group 2 – Grengloo, Group 3 - Brace Paste &amp; Group 4 – Enlight + UV dye additive. Debonding of brackets were done in INSTRON and evaluated for ARI score in stereo microscope and photo micrographs were taken to analyze the surface area in ImageJ software with conventional and UV light source. Then the adhesive remnants were removed with tungsten carbide bur at low speed with appropriate illumination and the enamel surface is assessed under scanning electron microscope for EDI score. This study resulted with time taken for the removal of adhesive remnants between the 4 groups and indicates statistically significant difference (p&amp;#60;0.05). Group 3 (Brace Paste) possesses the less time taken for the removal of adhesive remnants between the other three groups and shear bond strength reveals a statistically significant difference (p&amp;#60;0.05) between the three adhesive groups. This current study concluded that the color changing adhesives with the fluorescence property were significantly different when compared with other adhesives due to the reduction in time taken for the removal of adhesive remnants from the enamel surface with minimal damage. Additionally the introduction of a UV dye additive for the visual distinction between the enamel structure and adhesive remnant also proves to be a valuable aid in the assessment of adhesive remnant index and removal.

The Influence of Cryogenic Treatment on the Tribological Properties of Tungsten Carbide

Improvement in wear resistance and hardness of cutting tool material is one of the most critical challenges in machining operations. This issue can be addressed by enhancing wear resistance and hardness through cryogenic treatment of tungsten carbide. This study investigates the effect of different soaking periods during cryogenic treatment on commercially available tungsten carbide. Experiments were conducted at a temperature of 88K with varying soaking periods of 8 hours, 20 hours, 24 hours, and 30 hours. To quantify and confirm the impact of different soaking periods on hardness and wear resistance, Rockwell hardness measurements and weight loss during wear tests were performed. The results indicate a significant decrease in weight loss for the sample soaked for 8 hours compared to other soaking periods, although there was no change in bulk hardness. The reduced weight loss during the sliding wear test suggests that cryogenically treated tungsten carbide exhibits improved wear resistance due to an increased population density of carbides. Microstructural analysis of the worn surface reveals the mechanism behind the enhanced mechanical properties. Key Words: Cryogenics, dct, sct, microstructure, soaking period, tool life.

Effect of tungsten carbide and titanium dioxide particles on the properties of aluminium alloy 5052 hybrid composites

AbstractAerospace and automotive industries, among others, utilize reinforced aluminium metal matrix composite materials extensively. Aluminium alloy 5052 matrix was reinforced with tungsten carbide and titanium dioxide particulate reinforcements by varying their weight fractions, to fabricate the hybrid composites. The melt‐stir casting route was used to process the materials, and their characteristics were determined by measuring Vickers microhardness, tensile strength and peak elongation. The cost‐effectiveness and productivity of the melt‐stir casting route led to its selection. Investigations were carried out to assess how reinforcement particles were mixed into the aluminium alloy matrix using scanning electron microscopy and energy‐dispersive x‐ray analysis. The microstructure of aluminium alloy 5052 showed a distinct homogenous structural integrity. Adding tungsten carbide and titanium dioxide particles to aluminium alloy 5052 led to a 6.57 % rise in the Vickers microhardness value. The tensile strength of the hybrid composites made of aluminium, tungsten carbide, and titanium dioxide increased by as much as 8.7 %. The findings demonstrated that all of the hybrid composites failed due to particle fracture and ductile fracture in the case of the as‐cast aluminium alloy 5052.

High temperature tribological properties of additively manufactured WC reinforced CuAl7–W composites

A wear-resistant composite material based on aluminum bronze with an addition of tungsten and tungsten carbide particles is developed using a combined wire- and powder-feed additive electron beam technology. The wear tests conducted under dry sliding conditions at room and elevated temperatures demonstrate a significant increase in wear resistance without any significant changes in the friction coefficient. Specifically, the composite with a particle content of 10 % exhibits an average wear rate 1.6 times lower compared to that of pure aluminum bronze, while the composite with a particle content of 20 % shows a 3.9-times wear rate reduction. The wear of the steel counterfaces during the composite sliding remains close to the values observed in a similar process for pure bronze.

Thermally Sprayed Coatings for the Protection of Industrial Fan Blades.

This paper presents a study on thermally sprayed coatings. Coatings produced by high-velocity oxygen-fuel spraying HVOF and plasma spraying deposited on the A03590 aluminum casting alloy are tested. The subject of this research concerns coatings based on tungsten carbide WC, chromium carbide Cr3C2, composite coatings NiCrSiB + 2.5%Fe + 2.5%Cr, mixtures of tungsten and chromium powders WC-CrC-Ni, mixtures of carbide powders with the Cr3C2-NiCr + the composite 5% NiCrBSi and WC-Co + 5% NiCrBSi. The aim of this research is to find a coating most resistant to the erosive impact of particles contained in the medium centrifuged by industrial rotors. The suitability of the coating is determined by its high level of microhardness. The hardest coatings are selected from the coatings tested and subjected to abrasion tests against a sand particle impact jet and the centrifugation of a medium with corundum particles. It is found that the most favorable anti-erosion properties are demonstrated by a coating composed of a mixture of tungsten carbide and chromium carbide WC-CrC-Ni powders. It is concluded that the greatest resistance of this coating to the erosive impact of the particle jet results from the synergistic enhancement of the most favorable features of both cermets.