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The motivation of the present study is to gain insights into the evolution of elastic properties of cemented tungsten carbides (WC) shock compressed to 100 GPa. Seven plate impact experiments—two front surface impact and five release wave overtake—are conducted to make simultaneous measurements of Hugoniot states and longitudinal sound speeds in shocked WC with 3.7wt.% cobalt binder. The sound speeds along with estimates for bulk sound speeds, obtained using the Birch–Murnaghan EoS, are analyzed to determine the elastic moduli—longitudinal, bulk, and shear—as a function of Hugoniot stress. The longitudinal and bulk sound speeds at Hugoniot states of interest are found to increase linearly with longitudinal stress. Consistent with the increase in sound speeds, the longitudinal and bulk moduli also increase with Hugoniot stress; however, the increase in longitudinal modulus is modest when compared to predictions of theoretical models that account for pressure and temperature dependence of elastic moduli, but with no damage. The shear moduli remain nearly constant at ∼ 318 GPa over the range of Hugoniot states investigated. These values are, however, much lower than those predicted by the Steinberg–Guinan model with no damage. Poisson's ratio decreases initially from its ambient value of 0.208 to ∼ 0.199 for Hugoniot stress ≤ 10 GPa indicating consolidation of the WC microstructure with low initial stress; however, with an increase in Hugoniot stress to ∼ 100 GPa, Poisson's ratio increases to ∼ 0.317, indicating degradation of shear moduli with increasing stress. The product of density and Grüneisen parameter (ρ Γ), after an initial spike, remains nearly constant for volumetric strains ≥ 0.07. The maximum average temperature rise is estimated to be ∼ 286 ° C at the highest Hugoniot stress employed in the study. [ABSTRACT FROM AUTHOR]

Plate impact experiments are conducted on cemented tungsten carbides (WC) with a 3.7 and 6.0 wt. % cobalt binder to better understand their dynamic, high-pressure response to 100 GPa. The measured wave profiles show propagation of steady structured waves. Standard impedance matching procedures are used to determine the Hugoniot relations in the shock velocity–particle velocity (U s − v p) and Hugoniot stress–specific volume (P − V / V o) planes. The Hugoniot elastic limit of the samples is controlled by ductility of the Co binder and is determined to be 4.45 ± 0.29 GPa for cemented WC with 3.7 wt. % cobalt and 3.72 ± 0.24 GPa for a 6.0 wt. % cobalt binder. Both grades show a non-linear U s – v p relationship depending on whether the particle velocity is in the strength dominated or hydrodynamic regime. In the strength dominated regime, a non-linear decrease in U s is observed as v p increases from ambient to the material's hydrodynamic limit. In the hydrodynamic regime, the U s – v p Hugoniot is linear and is determined to be U s = 4.97 (± 0.006) + 1.446 (± 0.018) v p km/s for WC with 3.7 wt. % Co and U s = 4.93 (± 0.006) + 1.463 (± 0.017) v p km/s for 6 wt. % Co. Both WC grades indicate shear-stress hardening with mean stress immediately after yield, followed by pressure softening, and then a sharp fall in stress carrying capacity as the mean stress is increased to ≈ 70 GPa (hydrodynamic limit) and beyond. This behavior is in contrast to pure WC ceramics, which show continued shear-stress hardening with mean stress to ≈ 80 GPa. [ABSTRACT FROM AUTHOR]

Electrical and thermal measurements were conducted during the plasma electrolytic polishing (PEP) of cemented tungsten carbide (WC-Co) materials to characterize energetic aspects of the process in relation to the temporal development of the gaseous layer near the workpiece. The power transferred to the workpiece is determined using a calorimetric probe and employing the time derivative of the temperature curve. It shows distinct heating phases due to the generation of the gaseous layer. At the beginning of the process, a typical power of 367 ± 17 W is transferred to the workpiece of a surface area of 14 cm2. At longer process times, a stabilized gaseous layer limits the power transferred to the workpiece to 183 ± 3 W. In an attempt to describe the heat transferred to the electrolyte, the electrolyte temperature was measured using a thermocouple situated 15 mm away from the workpiece. The local electrolyte temperature increases from 70 to 81 °C for an immersion depth of 20 mm. Moreover, the spatiotemporal development of the electrolyte temperature was obtained by 2D-hydrodynamic modeling using COMSOL Multiphysics®. The modeling results for the local temporal temperature development are in excellent agreement with the experimental values when the turbulent model is applied up to t = 65 s. Afterward, the laminar model leads to a better agreement. Furthermore, line scan x-ray photoelectron spectroscopy revealed that aliphatic carbon was preferentially removed. Only a slight compositional gradient in the vertical direction after the PEP process was observed. [ABSTRACT FROM AUTHOR]

Nickel-based tungsten carbide composite coatings are extensively utilized on various wear-resistant workpiece surfaces due to their exceptional properties, including high hardness and wear resistance. However, as the WC content increases, uneven structure and susceptibility to cracking of the coating during the forming process are enhanced, thereby impacting its service performance. To address these issues, NiCuBSi/65WC composite coatings with varying tantalum (Ta) contents were fabricated on 42CrMo steel substrates by laser cladding. The influence mechanism of Ta content on the microstructure and wear resistance of the coatings was investigated. The results demonstrate that the addition of tantalum promotes the formation of reinforcement phases such as TaC and W 2 C in the coating. Moreover, with increased Ta content, the edge of WC particle reaction layers in the coating gradually transforms from sawtooth to shorter rod-shaped morphology. Additionally, as the Ta content increases, the dissolution degree of WC particles rises, thereby facilitating the formation of TaC and W 2 C compound carbide. This leads to an enhancement in both the quantity and uniform distribution of carbide reinforced phases within the coating, resulting in an increase in average coating hardness from 482.4 HV 0.2 to 580.1 HV 0.2. When the Ta content reaches 7 wt% in particular, no cracks are observed on the coating surface, and a uniform distribution of carbides is achieved. The relative wear resistance of NiCuBSi/65WC coating with 7 wt% Ta is approximately 2.36 times higher than that without Ta. [ABSTRACT FROM AUTHOR]

Tungsten carbides are important materials used in ceramic cements, machining tools, catalysts, sensors, and for hydrogen generation. Bulk W–C structures are highly complex; fundamental fully carburized WC and semi-carburized W 2 C are accompanied by structural transitions depending on the composition and temperature. The relationship between the structures, compositions, and temperatures is summarized in the W–C phase diagram. However, the high-temperature, stable, and single-crystalline nanoparticles related to the WC 1-x and W 2 C phases formed via energetic reactions accompanied by rapid cooling rates are not easy to determine considering the bulk phase diagram, and lead to fundamental questions regarding the origin of the nanophases. In this study, we propose a draft for the W–C nanophase diagram composed of the surface and gas-phase WC, WC 1-x , and W 2 C nanophases according to the composition and temperature. The model undergoes the process of a vapor–nanoliquid–nanophase starting from the gas-phase nucleation induced by an extremely high-temperature electrical explosion. In addition, the high-temperature reactivity and quenched nanophase, including its unique nanostructure, are related to the post-melt rheology, physical morphology, and steric hindrance of the solid matrix during an electrical explosion. [ABSTRACT FROM AUTHOR]

An experimental investigation was conducted to evaluate the machinability of a titanium alloy (Ti6Al4V) using copper (Cu), tungsten carbide (WC), and graphite (C) tools. Voltage (V), capacitance (pF), pulse-on time (Ton), and pulse-off time (Toff) were considered as the input machining parameters, whereas the material removal rate (MRR) and tool wear rate (TWR) were considered as the output machining parameters. A Taguchi L 1 6 orthogonal array and gray relational analysis (GRA) were utilized to design and optimize the machining parameters for both responses. Artificial neural network (ANN) analysis was performed to predict the experimental outcomes. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were used to assess the surface morphology and determine the elemental composition of the machined surface. The results indicated that the optimum machining conditions for the copper tool were 150 V, 1000 pF, 15 μ s (Ton), and 15 μ s (Toff). However, the optimal machining conditions for the WC were 200 V, 100 pF, 25 μ s (Ton), and 10 μ s (Toff), and the optimal conditions for the C were 200 V, 1000 pF, 20 μ s (Ton), and 25 μ s (Toff), respectively. The highest MRR achieved using the WC tool was 9.4510 mg/s, whereas the TWR of the Cu, WC, and C tools were 1.1039 mg/s, 1.0307 mg/s, and 1.2796 mg/s, respectively. The results showed that machining with the graphite tool had a higher TWR than machining with the Cu and WC tools. [ABSTRACT FROM AUTHOR]

In this investigation, the factors were oil type ( O t ), powder type ( T p ), and powder concentration ( C p ) level, and the machining parameters were the voltage (V), capacitance (pf), pulse-on time ( T on ), and pulse-off time ( T off ). The output parameters were the material removal rate (MRR), and tool wear rate (TWR). Three types of oils and powders, along with their respective particle concentrations, were selected for this experiment. Neem, Karanja, and sesame oils were mixed with aluminum oxide (Al2O3), chromium (Cr), and nickel (Ni) powder at 4, 6, and 8 gm/l, respectively, using an overhead stirrer to investigate the conditions under which the green oil powder mixed mixture yielded a higher MRR and lower TWR during the micro-EDM process of titanium alloy (Ti-6Al-4V) using a 0.8 mm tungsten carbide (WC) tool with fixed machining parameters (240 V, 100 pf, 20 μ s T on , and 5 μ s T off ). All the powders used in this experiment had a 32-micron (450 mesh) size. The Taguchi L 2 7 orthogonal array and grey relational analysis methods were used to design and optimize the input process parameters for both responses. SEM, optical microscopic analysis, and EDS analysis were performed to examine the surface morphology, characteristics of the WC tool, and elemental composition of both the tool and the workpiece material. The optimum conditions for Karanja oil with a Cr powder mixture concentration of 4 g/l resulted in higher MRR and lower TWR. However, machining with neem and sesame oils resulted in higher TWR and lower MRR. [ABSTRACT FROM AUTHOR]

WC-Co composites are widely used in cutting tools but are expensive and harmful due to Co in the composites. Alternatives, such as WC-Ni composites have inferior mechanical properties, as a result, WC-Co composites are used in most cutting tools. This study investigated whether adding yttrium oxide (Y2O3) to WC-Ni composites, fabricated from recycled tungsten carbide (WC) and Ni, improved their mechanical properties. Changes in the composites' microstructure and mechanical properties depended on the amount of Y2O3 added. Y2O3 reacted with WC during sintering, promoting the formation of W and reducing the proportion of C in the composite. The added Y2O3 accelerated the dissolution of W in the Ni matrix, and increased the fractions of the eta phase and solid solution phase. Ni is strengthened by the dissolution of W in Ni, thereby supplementing the low toughness of the eta phase and ultimately yielding WC – Ni with improved hardness and fracture toughness (HV: max. 15.4 GPa, KIC: max. 13.4 MPa∙m1/2) compared to WC – Ni without Y2O3 (HV: 13.5 GPa, KIC: 12.7 MPa∙m1/2). The method for improving the properties of WC – Ni composites by the addition of Y2O3 has a high possibility of commercialization because it does not necessitate process changes. [ABSTRACT FROM AUTHOR]

Today's industries need to be more productive, especially those that shape and machine materials. As a result, engineers and scientists are seeking for cutting tool materials and technologies that have high hot hardness, chemical stability, wear resistance, and toughness while also improving tool life or contact time. Cryogenic treatment of cutting tools has been proven to be a good way for increasing the contact time of any cutting tool material. This study presents the results of turning alloy steel (EN24 grade) using P20 grade carbide inserts under various conditions under continuous machining. Cutting speeds varied from 100 to 500 m/min (in increments of 100 m/min), with feed rates ranging from 0.1 to 0.4 mm/rev in stages of 0.1 mm/rev and a constant radial depth of cut of 1.5 mm were considered under dry machining conditions. Cryogenic treated/coated inserts are better than other inserts in terms of tool life for optimized parameters such as cutting speed 100 m/min, feed rate 0.1 mm/rev, and depth of cut 1.5 mm, according to the study's findings. Under similar conditions of cutting speed, feed rate, and depth of cut, coated/cryotreated inserts had a tool life increase of about 97.5% over uncoated/untreated inserts, a 50.58% increase over uncoated/crytreated inserts, and a 23.89% increase over coated and untreated inserts, respectively. [ABSTRACT FROM AUTHOR]

Hybrid metal matrix composites have emerged as an epicentre of material research due to their vast applications and a wide array of reinforcement combinations. In this experiment, two-step stir casting method had been used to fabricate hybrid aluminium 6061 metal matrix composites. The micro-structural and mechanical evaluation (density measurement, impact, tensile, hardness, and flexural) of the fabricated aluminium (AA6061) hybrid metal matrix composite had been performed. The reinforcements used were Al2O3 (3 wt.%), RHA (2 wt.%), WC (2 wt.%), and SiC (5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%). The mechanical properties had been found to improve with increasing wt.% of SiC. The maximum experimental density (2999.2 Kg/m3), impact energy (6 J), tensile strength (130.15 N/mm2), hardness (35 HRA), and flexural load (6720 N) had been obtained with 20 wt.% SiC reinforcement. The presence of reinforcements (Al2O3, RHA, WC, SiC) and their uniform distribution in the Al6061 matrix was confirmed by micro-structural analysis. Other surface morphological information like agglomeration of less soluble alumina and presence of dendrite structures at higher SiC concentration were also revealed. Further, the observations from this investigation have been compared with already existing literature. In conclusion, prospects for future research have also been explored. [ABSTRACT FROM AUTHOR]

A promising metal-organic framework (MOF) called Zeolitic Imidazolate Framework-8 (ZIF-8) stands out for its electrochemical applications. Its versatility in physicochemical properties makes it a strong candidate for breakthroughs in energy storage and electrochemical water splitting. The electrode nanomaterials lower specific capacity, small charging/discharging rate, and low conductivity limit its supercapacitor and hydrogen evaluation reaction (HER) applications. The ZIF-8 zeolite structure was decorated with tungsten carbide (WC) to overcome these issues. These modifications result in improved porosity, surface area, density, and pore size, shape, and structure. These characteristics contribute significantly to enhanced electrochemical activity. ZIF-8 MOF/WC nanocomposites have excellent dispersion and stability due to their porosity and strong connection between embedded WC nanoclusters and the framework. The prepared electrode showed a 118.11 mV overpotential and 36.45 mV/dec Tafel slope throughout HER activity. ZIF-8 MOF/WC was used for electrochemical studies and to make a hybrid energy storage device using activated carbon (AC). The hybrid supercapacitor had higher energy and power densities (87 W h/kg and 850 W/kg). The theoretical technique (Dunn model) was also employed to analyze experimental results more thoroughly. [Display omitted] • ZIF-8 MOF/WC composite used for supercapattery and electrochemical water splitting. • An outstanding specific capacity of 2182 C/g is obtained. • Astounding 87 Wh/kg energy and 850 W/kg power densities are proposed. • ZIF-8 MOF/WC exhibits a low η (118.11 mV@10 mA/cm2) and low Tafel slope (36.45 mV/dec). • Estimated 96 % capacity retention after 20000 charge-discharge cycles. [ABSTRACT FROM AUTHOR]

The Knoop hardness (HK) and compression strength (σc) of 23 advanced ceramics were measured to determine if an overarching HK/σc relationship could be identified for ceramics, or if one exists for a specific class of ceramics, similar to the hardness/yield strength relationship (H/Y ≈ 3) identified by Tabor for metals. Compression strength was determined using a dumbbell‐shaped specimen that virtually eliminates the end splitting that occurs when cylinders or cuboids are tested and provides a more representative compression strength value. HK values were obtained over a range of indentation loads between 0.98 and 98N. Four HK values, HK2, load‐independent HK, the hardness from the proportional specimen resistance model, and a brittleness parameter, were obtained and plotted against compression strength. An overarching relationship could not be identified for ceramics in general and the only class of ceramics that had a consistent relationship was tungsten carbide/cobalt that had a HK/σc of approximately 2.5. The consistent relationship for the WC/Co materials is due to the cobalt plastically deforming during the loading processes, something that does not occur in the other ceramics evaluated. [ABSTRACT FROM AUTHOR]

The effects of reduced graphene oxide (rGO) as an additive on the microstructure, mechanical properties, and tribological behavior of air plasma sprayed (APS) nanostructured tungsten carbide–cobalt (WC-25 wt.%Co) coatings were studied. The rGO was added in three distinct weight percentage proportions of 0.5, 1, and 1.5 wt.%. The microhardness and surface roughness of the APS sprayed nanostructured WC-25 wt.%Co coatings reinforced with rGO were changed significantly. Microstructural alterations in the coatings were also noticed with the addition of additives. Gluing of rGO amid coating splats was also seen in the microstructure of the coatings. The coatings' microstructure revealed the presence of tungsten (W), tungsten carbide (WC), and semi-tungsten carbide (W2C) as the primary phases. The existence of the W2C phase in the microstructure of the coatings was mostly due to the decarbonization of WC at higher temperatures during plasma spraying. It was also found that the amount of wear of the coatings was exceptionally low because the rGO could not be extracted from the 1.5 wt.% rGO-reinforced coatings particularly. The wear degradation in the 0.5 and 1.0 wt.% rGO added coatings was mostly due to delimitation and the subsequent pulverization, notably at loads and sliding speeds of 1.5 kgf and 0.17 m/s. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Microwave sintering (MS) technology is used to fabricate UNS R56320 (Ti-3Al-2.5V)-xWC composite at 1200 °C. In the matrix, tungsten carbide (WC) is reinforced with various weight percentages of 0.5, 1.0, 1.5, and 2.0. A field emission scanning electron microscope is used to characterize the composites (FE-SEM). X-ray diffraction was used to analyze the composites' phase analysis (XRD). Microstructure, wear at high temperatures, and corrosion behavior are evaluated. For the composites at different temperatures of 30 °C, 50 °C, 100 °C, 150 °C, and 200 °C, the high-temperature wear is examined. The outcomes show improvements in the behaviors of corrosion and wear at high temperatures. TAFEL polarization is used to evaluate the corrosion behavior of the composites in a neutral chloride solution (3.5% NaCl). The composite material UNS R56320-2WC has a maximum wear rate of 0.49 × 10−3 mm3/m and a coefficient of friction of 0.50. A higher level of corrosion resistance than other composites is also possessed by UNS R56320-2WC composite. [ABSTRACT FROM AUTHOR]

In order to enhance the hardness and wear resistance of 316L alloy, a strengthening phase was incorporated and laser-directed energy deposition was utilized to create a composite deposition layer consisting of coarse WC/316L, fine WC/316L, and coarse/fine WC/316L. Microstructural observations, phase composition analysis, Vickers hardness testing, interfacial coupling analysis, x-ray diffraction (XRD), and evaluation of friction-wear performance were systematically performed on the deposited samples. These investigations were undertaken to elucidate the impact of incorporating WC particles on both microstructural features and wear characteristics. Results showed that the average grain size of the composite deposition sample with coarse WC/316L decreased by 24% compared to 316L, with a 15.9% increase in hardness and a 97.6% decrease in wear rate. Similarly, the fine WC/316L composite deposition sample saw a 23% reduction in grain size, a 6.4% hardness increase, and a 62.4% decrease in wear rate compared to 316L. The hardness increased by 6.4%. The wear rate decreased by 62.4%. The coarse/fine WC/316L composite deposition samples exhibited a 34% decrease in average grain size, a 35.9% hardness increase, and a 99.1% decrease in wear rate compared to 316L. The addition of WC significantly enhanced the properties of 316L alloy, with coarse/fine WC showing the most significant improvements in microhardness and wear resistance. [ABSTRACT FROM AUTHOR]

We have established a method for the simultaneous measurement of element abundances and boron isotopic compositions of bulk‐rock silicate samples by laser ablation coupled to two different ICP‐MS instruments. Fifteen silicate reference materials were prepared as micro‐particulate pressed powder pellets (MP) for analysis. Approximately 1/5th of the ablated material was transported to a single‐collector ICP‐MS for elemental measurement, while 4/5ths were sent to a multi‐collector ICP‐MS for boron isotope ratio measurement. Compositions of different milling materials (agate, zirconium oxide, tungsten carbide, sintered corundum and silicon nitride) were measured for the evaluation of potential contamination during sample preparation. Determined element mass fractions are in agreement with literature values within ±20%. For boron isotope ratios, the matrix‐dependent background elevation across the m/z from 9.9 to 11, and the effect of ablation mass was quantified. Measured δ11B values of most reference materials are consistent with literature values within ±1‰. The intermediate measurement precision is ±0.3‰ for JB‐2 with 30 μg g−1 B and ±0.4‰ for JA‐2 with 21 μg g−1 B. A publically available, web‐based streamlit app was developed for data processing (https://zenodo.org/doi/10.5281/zenodo.11150471). This paves the way for combined, accurate and precise elemental and boron isotope ratio measurements of geological materials. [ABSTRACT FROM AUTHOR]

Tool wear is a key issue for the manufacturing performance of refill friction stir spot welding in high-volume manufacturing environments. As such, the aim of this study is to examine conditions in which tungsten carbide with a cobalt binder can succeed as a tool material in the spot welding of 2029 aluminum for a sustained lifetime. Critical factors are shown herein to include cleanliness and thermal management. The life of a WC-Co toolset is demonstrated to be approximately 2998 welds, which is of the same scale as conventional steel tooling. With a WC-Co shoulder and probe, the H13 clamp showed the only significant wear. [ABSTRACT FROM AUTHOR]

The study investigated the wear rate dependences of diamond-impregnated drill bits consisting of composite diamond-containing materials (CDMs): specifically, 25Cdiamond–70.5WC–4.5Co and 25Cdiamond–68.62WC–4.38Co‒2ZrO2. These materials were fabricated via spark plasma sintering at temperatures ranging from 20 to 1350°C under a pressure of 30 MPa for 3 min. Testing was conducted under rotational speeds and axial load conditions typical for granite drilling. It was demonstrated that incorporating 2 wt % of ZrO2 nanopowder into the composition of 25Cdiamond–70.5WC–4.5Co resulted in a threefold reduction in wear rate. The highest wear resistance of these diamond-impregnated drill bits was observed at rotational speeds of 250 rpm and axial loads of 900 kg, as well as at 750 rpm and 1250 kg axial load. Comparatively, the enhanced wear resistance of diamond-impregnated drill bits made from 25Cdiamond–68.62WC–4.38Co‒2ZrO2, in contrast to those made from 25Cdiamond–70.5WC–4.5Co, can be attributed to factors such as finer grain size, higher relative density, improved strength under compression and bending, increased fracture toughness, and the formation of strong bonding between diamond grains and the hard-alloy matrix. These findings, combined with the fine-grained structure of the hard-alloy matrix and high diamond retention, indicate that these diamond-impregnated drill bits have potential for application in developing new tools with superior operational properties for drilling hard rock formations. [ABSTRACT FROM AUTHOR]

The influence of the introduction of tungsten carbide nanocrystalline on the microstructure and mechanical characteristics of Ni-WC composite overlays on tool steel was studied. In addition to the improved fraction of retained WC phase and decreased fraction of brittle secondary carbide phases, the influence of the addition of tungsten carbide in nano-size on the microstructure, and mechanical behaviors of the deposited layer was considered. Tungsten carbide nanoparticle in the range 1-7 wt.% was added to existing commercial powder and deposition was carried out. The optimum welding parameters were determined. The results showed that the Ni-WC overlays possessed microstructures including γ-Ni dendrites, with interdendritic Ni-Fe-based eutectics, borides (Fe-Cr)2B, and carbides (Fe, Cr)7C3. With the introduction of WC-nanocrystalline, refining the microstructure was achieved and the dissolution of WC particles enhanced the generation and growth of secondary carbide phases. The strengthening contribution of the reinforcing particles in alloy with 3 wt.% causes an increase in hardness, while the hardness values decrease as the content of WC increases by 7 wt.%. [ABSTRACT FROM AUTHOR]

[Display omitted] The pursuit of efficient and sustainable hydrogen production through water splitting has led to intensive research in the field of electrocatalysis. However, the impediment posed by sluggish reaction kinetics has served as a significant barrier. This challenge has inspired the development of electrocatalysts characterized by high activity, abundance in earth's resources, and long-term stability. In addressing this obstacle, it is imperative to meticulously fine-tune the structure, morphology, and electronic state of electrocatalysts. By systematically manipulating these key parameters, the full potential of electrocatalysts can unleash, enhancing their catalytic activity and overall performance. Hence in this study, a novel heterostructure is designed, showcasing core–shell architectures achieved by covering W 2 N-WC nanowire arrays with tri-metallic Nickel-Cobalt-Iron layered triple hydroxide nanosheets on carbon felt support (NiCoFe-LTH/W 2 N-WC/CF). By integrating the different virtue such as binder free electrode design, synergistic effect between different components, core–shell structural advantages, high exposed active sites, high electrical conductivity and heterostructure design, NiCoFe-LTH/W 2 N-WC/CF demonstrates striking catalytic performances under alkaline conditions. The substantiation of all the mentioned advantages has been validated through electrochemical data in this study. According to these results NiCoFe-LTH/W 2 N-WC/CF achieves a current density of 10 mA cm−2 needs overpotential values of 101 mV for HER and 206 mV for OER, respectively. Moreover, as a bi-functional electrocatalyst for overall water splitting, a two-electrode device needs a voltage of 1.543 V and 1.569 V to reach a current density of 10 mA cm−2 for alkaline water and alkaline seawater electrolysis, respectively. Briefly, this research with attempting to combination of different factors try to present a promising stride towards advancing bi-functional catalytic activity with tailored architectures for practical green hydrogen production via electrochemical water splitting process. [ABSTRACT FROM AUTHOR]

In this study, binderless WC ceramics with grain size of 210 nm were obtained under a high-pressure of 200 MPa at a relatively low temperature of 1550 °C. The effects of high pressure on the densification behavior and grain growth were investigated. Increasing the sintering pressure accelerated the densification rate, decreased the sintering temperature, and inhibited grain growth. HRTEM observations revealed highly stable Σ 2 grain boundaries and numerous microscopic defects (stacking faults and Lomer-Cottrell locks), with dislocation density up to 4.26×1015 m−2. High-pressure strengthening effect enhanced the hardness and wear resistance by inducing plastic deformation. The high-pressure sintered WC ceramics exhibited enhanced hardness of 32.19 GPa and excellent tribological properties. Compared with the low-pressure samples, the hardness increased by 23%, the friction coefficient reduced by 30%, and the wear resistance improved by 63%, which were mainly related to the fine-grained microstructure, stable Σ 2 grain boundaries, and high-density defects. [ABSTRACT FROM AUTHOR]

In the current study, micro-electric discharge drilling (µEDD) is conducted on a titanium grade 2 alloy using a tungsten carbide (WC) tool electrode of 496 µm diameter. Capacitance, voltage, and feed rate are selected as machining variables to conduct the experiments based on the full factorial experimental design method. Overcut, material removal rate (MRR), circularity, and hole taper are considered as performance measures. Furthermore, overall evaluation criteria (OEC) is utilized for multiple-objective optimization by allotting varying and equal weight percentages to each response measure. The results of OECs are compared with a revolutionary heuristic multi-objective genetic algorithm (MOGA), resulting in a similar optimal parametric combination and close response measures are obtained. Micrographic investigation demonstrates that at lower capacitance and voltage levels, there is less burr formation, recast layer, and circularity error. Moreover, FESEM and EDS analyses are employed to investigate the machined surface topology and elemental composition respectively. [ABSTRACT FROM AUTHOR]

The adhesion strength of the solid phase boundary in the Ge20Se80 glass–substrate (quartz glass, stainless steel, tungsten carbide) systems was measured using the normal separation method in the temperature range of 270 – 360°C. The maximum work of adhesion of chalcogenide glass among the studied structural materials was observed for stainless steel with a non-nitrided surface. The wetting and adhesion of the Ge20Se80 glass melt to structural materials in the temperature range of 370 – 470°C were investigated. The maximum adhesion of the chalcogenide melt is observed for the surface of quartz glass, while the minimum is observed for the surface of nitrided stainless steel. [ABSTRACT FROM AUTHOR]

The unique mechanical properties of Tungsten Carbide (WC), such as fracture toughness, exceptional hardness, high melting temperature, outstanding thermal stability, anti-oxidation qualities fatigue and creep resistance, have made it a suitable industrial material for different applications. It is also considered to be a promising material for coating on plasma-facing walls in a Tokamak reactor. The aim of the present work is to study the effect of varying substrate temperature, concentration of tungsten (W) and annealing in the structural properties of WC films. The WC films are deposited on a silicon substrate at different substrate temperatures viz. RT (300 K), 400, 500, 600 and 700 K using DC magnetron sputtering. W-rich WC films were deposited keeping the power of WC constant (100 Watt) and varying W powers (10 Watt, 20 Watt, 30 Watt, 40 Watt) at room temperature. Later, these W-rich WC films were annealed at 800°C in a reducing atmosphere. Glancing incidence X-ray diffraction (GIXRD) and Raman spectroscopy of the films are performed for structural analysis. GIXRD of the WC films reveals that as-deposited RT films are amorphous. However, films which are either deposited at elevated substrate temperature or are annealed are crystalline. This is confirmed by Raman's measurements. It also indicates the presence of disorder and nanocrystalline phases due to temperature variations. [ABSTRACT FROM AUTHOR]

Intertrack fluctuation of microstructure and mechanical properties is one of the important characteristics for nonuniformity in laser cladding processes. The understanding of the fluctuation helps to improve the wear resistance of deposited materials. In this paper, the phase structure, element distribution, hardness variation and carbides were identified and compared between the cladding zone (CZ) and the heat-affected zone (HAZ) in T15 steel laser cladding. A calculation method was proposed to reveal the physics of the solidification and precipitation behavior of carbides by combining the finite element method (FEM) and thermodynamic calculations. The results showed that the hardness of the intertrack HAZ was higher than the hardness of the CZ due to the high amount and small size of vanadium carbide (VC) particles. The calculation proved that the major strengthening phase was VC precipitate, while tungsten carbide (WC) was not stable in the cooling process and converted to Fe3W3C. The volume fraction of VC in the HAZ was 14.3%, which was higher than the volume fraction in the CZ, which was only 10.0%. The high temperature was prone to a high volume fraction and many VC precipitates with a small radius in the intertrack HAZ, which qualitatively agreed with the experimental characterization. [ABSTRACT FROM AUTHOR]

Purpose. Development of highly effective composite diamond-containing materials based on WC‒Co matrices with CrB2 additives with improved mechanical and performance properties for creating matrices of rock-cutting tools for drilling oil and gas wells. Methodology. The assigned tasks were solved using a comprehensive research method, which includes a review and synthesis of literary sources; conducting analytical studies of existing composite diamond-containing materials; scanning electron microscopy (SEM) methods; X-ray phase analysis methods; calculation of experimental data by the Rietveld method, developed for the characterization of crystalline materials by powder X-ray diffraction; the Williamson-Hall technique. Findings. It has been established that the structure of the initial 94 %WC–6 %Co composite consists of WC phases with crystal lattice parameters a = 0.2906, c = 0.2837 nm and graphite with lattice parameters a = 0.2461, c = 0.6708 nm. The addition of chromium diboride to the composition of the 94 %WC–6 %Co sample leads to the decomposition of the CrB2 phase and the formation of the final phase composition: WC + B2CoW2 + Cgraphite + solid solution of tungsten and carbon in cobalt. Originality. It was shown for the first time that if the WC–6Co system is characterized by insignificant solubility of the components in each other, then in the WC–Co–CrB2 system there is a significant mutual dissolution of the components, which leads to a decrease in their sizes during the sintering process. When the threshold concentration (~4 %) of chromium diboride in the charge is reached, phases of the hexagonal WC group and new phases of the orthorhombic group B2CoW2 and amorphous carbon inclusions begin to form in the structure of the composite. Practical value. A highly effective composite diamond-containing material based on WC‒Co matrices with CrB2 additives with increased mechanical (hardness, crack resistance, compressive and bending strength) and operational (wear resistance, productivity) properties has been developed to create a highly effective rock-cutting tool for drilling oil and gas wells. [ABSTRACT FROM AUTHOR]

The scientific and industrial communities now consider surface modification of steel-based alloys to be essential. One effective method of altering these alloys' surfaces is tungsten inert gas (TIG) cladding. The purpose of this study is to investigate how the surface characteristics of austenitic stainless steel substrates are affected by TIG-deposited composite coatings made of tungsten carbide and nickel (WC-Ni). The study also intends to investigate the influence of the WC-Ni composite coatings' travel speed, and as a result, the heat input usually has significant effects on the microstructure. The coating layers were deposited at different travel speeds (67, 107, and 122 mm/min) using preplaced composite pastes that were 1 mm thick and contained the same weight percentage of WC (65). The clad layers showed a variety of microstructures in optical and scanning electron microscopy, primarily nickel solid solution dendrites with WC particles scattered throughout the matrix. The dendrites at various locations across the clad layers were few or dense, finer or coarser, equiaxial or columnar, densely or less densely branched, depending on the cooling rates and the density of WC in the composite. Energy dispersive spectroscopy demonstrated that the Fe element that was transferred from the substrate material to the molten pool was primarily concentrated in the matrix, not the dendrites, while the dendrite locations and orientations were amply demonstrated by the distribution of the W element. [ABSTRACT FROM AUTHOR]

The study aims to fill the gap in the existing literature by investigating the effects of various tool materials, including copper, tungsten carbide, and brass, on performance parameters in electric discharge machining (EDM) simulations. The authors developed a modified gaussian heat flux equation that incorporates the electrical resistivity of both the tool and workpiece, based on prior experimental investigations. The authors further developed a finite element model that incorporates the modified Gaussian heat flux equation, spark radius, and fraction of heat transferred to workpiece as a function of pulse on time and pulse current, latent heat, specific heat values, and thermal conductivity properties. The outcomes of the simulation indicated that the Cu tool exhibited the minimum MRR and SR values when subjected to a current of 9 amps and a duty cycle of 0.4, as well as a current of 12 amps and a duty cycle of 0.6. The results also indicate that the brass tool displayed marginally elevated MRR and SR, whereas the Tungsten carbide tool exhibited the highest MRR and SR. The simulation results for all three tool materials showed similar trends, consistent with prior research. Also, an increase in gap voltage, pulse current and duty cycle was observed to correspond with increased MRR and SR. Authors also observed that as electrode material electrical conductivity increased, so did workpiece material residual stresses. These results assist with the choice of tool materials for EDM processes, allowing for finer control over performance parameters and greater machining efficiency. [ABSTRACT FROM AUTHOR]

Flash sintering was officially discovered about fifteen years ago as a ground-breaking method to consolidate ceramics in very short time at furnace temperature much lower than that used for conventional sintering. Since then, it has been applied to several ceramics and composites with the common feature of being characterized by a negative temperature coefficient for resistivity while few attempts have been made on materials with metal-like electronic conduction. In the present overview the results of the investigation carried out in the last years aiming at consolidating tungsten carbide and zirconium diboride by flash sintering are reported and the conditions for inducing a thermal runaway phenomenon like in other ceramics and understand the physical mechanisms behind the flash effect are analysed. The investigation allows to point out the importance of the fundamental processing variables like the applied pressure and voltage for obtain high density material. The key role of the starting particles' surface chemistry is identified to generate specific microstructures and determine peculiar physical and mechanical properties in the flash sintered ceramic. [ABSTRACT FROM AUTHOR]

Tungsten carbide (WC), renowned for its exceptional hardness and wear resistance, plays an essential role in various industrial applications (cutting tools, abrasives, and wear-resistant components). While traditional methods involve hot pressing, Spark Plasma Sintering (SPS) combined with Additive Manufacturing (AM) offers a cutting-edge approach, utilizing high-voltage electric current and mechanical pressure for rapid densification, particularly advantageous for fabrication of complex shape components made from challenging materials like nanosized binderless tungsten carbide. The study encompasses the entire spectrum of the powder's characterization, extending to the development of an intricate finite element simulation tailored for SPS sintering. Sintering cycles underscore the exceptional quality of the powder, demonstrating full density microstructures even under low-temperature (1550 °C) and low-pressure (50 MPa) conditions. The nanosized powder exhibits minimal microstructural coarsening, reflecting the high quality of the initial pure tungsten carbide nano powder. The core of this study revolves around the methodology employed for deriving constitutive parameters, following the Skorohod-Olevsky theory of continuum sintering. The derivation methods include variations in temperature, heating regimes, and stepwise pressure application during SPS. Additionally, a grain growth model is formulated based on microstructural analysis. Critical parameters, including the apparent sintering activation energy (800 kJ/mol) and the creep law stress exponent (n = 4.0), are discussed. The article concludes with the integration of the mechanical sintering model into finite element method (FEM) software, considering thermal and electrical aspects for a comprehensive SPS-AM modeling approach and its application to complex shape production. The research aims to enhance the understanding of SPS for tungsten carbide, providing insights for its application in manufacturing cutting-edge components in challenging environments. [ABSTRACT FROM AUTHOR]

Doping or partially substituting WC with metals, e.g., Mo and Cr, can lower its density while keeping the strength of the modified carbides similar to that of WC, making them attractive as the reinforcement for hardfacing overlays and tool steels, since they can be distributed homogeneously in the metal matrix. However, it is unclear if the doped WC has desirable interfacial bonding with the matrix, e.g., iron. In this study, we investigated the interfacial bonding of Mo- and Cr-doped WC, compared to that of mono-WC, with austenite and ferrite irons via first-principles calculations. (11 2 ¯ 0) C a r b i d e / / (110) F e , (10 1 ¯ 0) C a r b i d e / / (100) F e , and (0001) C a r b i d e / / (100) F e interfaces for both ferrite and austenite with the lowest interfacial mismatch were investigated. Characteristics of the formed interfacial bonds were studied based on the electron localization function, electronic density of states, bond order, and net charge. It was demonstrated that the Mo and Cr-doped WC carbides, (W4−x, M)C4, show comparable or higher adhesive work with iron, compared to that of mono-WC with iron. The metal-substituted or doped W4C4 carbides are promising replacements of heavier WC for tool steels and ferrous hardfacing overlays. [ABSTRACT FROM AUTHOR]

Due to the limitation of the supersonic flame spraying process method，the axle sprayed with tungsten carbide must ensure the surface roughness and dimensional accuracy through the grinding process，but the weak machining rigidity of the axle and the high wear resistance of the coating lead to the phenomenon of making the cutting tool and shaking the cutting tool in the grinding process，resulting in the unqualified grinding quality of the parts. Firstly，the influence of four fine grinding process parameters on the grinding surface roughness is studied by orthogonal experimental method. Then，the influence of clamping tools and grinding strategies on the cylindricity of parts is studied. Finally，the outer dimensions of the individual sections of the 15 axles are machined and collected and their process capability indices are calculated. The results show that the surface of the part with roughness of Ra0.4 can be obtained by selecting high grinding wheel linear velocity，small depth of cut and moderate grinding wheel axial feed rate and workpiece linear velocity，increasing the clamping length and rigidity of the clamping tool，and adopting the strategy of "coarse grinding-fine grinding-smooth grinding" to ensure that the cylindricity of the outer circle of the part is not more than 0.01 mm. The axle process capability index is not less than 1.33，and the entire grinding process is reliable and stable.

A composite material of tungsten carbide and mesoporous carbon was synthesized by the sol-gel polycondensation of resorcinol and formaldehyde, using cetyltrimethylammonium bromide as a surfactant and Ludox HS-40 as a porogen, and served as a support for Pd-based electrodes. Phosphorus-modified Pd particles were deposited onto the support using an NH3-mediated polyol reduction method facilitated by sodium hypophosphite. Remarkably small Pd nanoparticles with a diameter of ca. 4 nm were formed by the phosphorus modification. Owing to the high dispersion of Pd and its strong interaction with tungsten carbide, the Pd nanoparticles embedded in the tungsten carbide/mesoporous carbon composite exhibited a hydrogen oxidation activity approximately twice as high as that of the commercial Pt/C catalyst under the anode reaction conditions of proton exchange membrane fuel cells. [ABSTRACT FROM AUTHOR]

Photothermal therapy is a new, promising approach for treating cancer in a noninvasive way. Herein, a photothermally efficient nanomaterial is synthesized by exposing bulk WS2 powder, dispersed in carbon‐rich acetonitrile, to high‐intensity femtosecond laser pulses. The photothermal measurements show a significantly higher rise in temperature and enhance photothermal efficiency for the laser‐treated material. The attribution is on the enhancement to the formation of tungsten semi‐carbide (W2C), which is verified by morphological and structural characterization. The tungsten semi‐carbide is formed by laser‐induced carburization; intense laser pulses knock S atoms out of the WS2 lattice and dissociate the acetonitrile molecules, resulting in the formation of W2C. Interestingly, the hexagonal W2C has a two‐dimensional (2D) layered morphology like that of the WS2, suggesting its morphology is not random and might be determined by the morphology of the parent material. The study provides a simple route to transform a 2D transition‐metal dichalcogenide into a 2D transition‐metal carbide, which is useful for applications including photothermal therapy. [ABSTRACT FROM AUTHOR]

After single-point diamond turning (SPDT), a considerable number of turning marks are typically generated on tungsten carbide molds surface, which can adversely affect their service performance. To eradicate these marks and achieve a sub-nanometer surface roughness, shear thickening polishing (STP) technology is employed to finish the tungsten carbide surface after SPDT process. Three polishing slurries with different abrasives were employed: 5 wt% SiO 2 slurry with average particle size of 80 nm, 1 wt% polycrystalline diamond slurry with average particle size of 0.5 μm, and 1 wt% monocrystalline diamond slurry with average particle size of 0.5 μm. The influence of these slurries on the polishing performance was comprehensively evaluated, covering parameters including material removal rate (MRR), surface roughness (S z), surface roughness (S a), and surface topography. All experiments and measurements in this study were repeated three times, and the average values were taken as the final results to ensure the accuracy of the experiments. The results indicated that SiO 2 exhibited the lowest polishing efficiency and yielded the poorest surface roughness. Monocrystalline diamond performed better, while polycrystalline diamond not only demonstrated superior efficiency but also achieved sub-nanometer finishing. During the shear thickening polishing process, the solid phase particles in the polishing slurry gradually encapsulate the abrasive particles, forming a "flexible fixed abrasive" which effectively removes the turning marks and reduces the surface roughness (S a) to a sub-nanometer level of 0.9 nm. Through the selection of appropriate polishing angles, the S a was further reduced to 0.8 nm. The materials removal mechanism in STP process was elucidated from two perspectives: the wear mechanism of abrasive and the influence of the impurities. Finally, STP process with selected conditions was applied to finish an curve surface of optical mold, and the surface roughness (S a) reduces from 7.7 nm to 1.6 nm. This study provides a novel approach for the ultraprecesion finishing for optical molds with complex surface. • The surface roughness S a of tungsten carbide is reduced from 4 nm to 0.8 nm within 5 min' shear thickening polishing. • Polycrystalline diamond can balance high removal rate and high surface quality due to its high hardness and smooth edges. • The impurities Cr and Ni get removed in a large amount compared to the WC which explains why pits generate. • It provided a sub-nanometer finishing method for optical molds with complex surface. [ABSTRACT FROM AUTHOR]

The hardness and brittleness of binderless tungsten carbide, make it difficult to fabricate microlens array (MLA) on it. In this paper, an integrated milling-grinding machining method was used to fabricate MLA on binderless tungsten carbide. A model for predicting the relationship between surface roughness and undeformed chip thickness during the integrated milling-grinding process was proposed. Microgroove machining experiments confirmed the relationship between surface roughness and undeformed chip thickness, which showed that the ductile-brittle transition boundary was divided. Based on this, an MLA was fabricated in the ductile mode, and the surface roughness of a single lenslet was approximately 16 nm. This integrated milling-grinding machining method is shown to be available for fabricating MLAs on hard substrates. • It is hard to fabricate microlens array on binderless tungsten carbide, integrated milling-grinding is proposed. • The integrated milling-grinding contains milling of the tool edge and grinding of the diamond grains. • Microgroove machining experiments validates the relationship between surface roughness and undeformed chip thickness. • Lenslets with high surface quality and little tool wear are obtained after machining microlens array. [ABSTRACT FROM AUTHOR]

Fabricating and introducing new materials with new features is one of the most important goals for many scientific groups. Today, additive manufacturing (AM) is known as one of the new production methods, which can create an excellent opportunity for achieving this goal. As one of the ongoing production processes, the laser AM (LAM) methods have the proper capacity for producing new advanced materials like carbide, nitride, and boride‐based materials. Hence, this work aims to review carbide‐based materials produced by LAM techniques with the composite viewpoint. These materials can act as a matrix, reinforcement, or tertiary component in advanced composites. With this viewpoint, these composite materials were introduced in eight separate sections, which are tungsten carbide, titanium carbide, silicon carbide, niobium carbide, chrome carbide, vanadium carbide, and boron carbide, as well as high entropy alloy composites. [ABSTRACT FROM AUTHOR]

Tungsten carbide was manufactured by picosecond laser in this study. Shapes of the ablated craters evolved from parabolic‐like (less than 10 pulses) to Gaussian‐like (more than 500 pulses) as the pulse number increased. The shape changes were closely associated with the discontinuous diameter expansion of ablated crater. To explain these phenomena, two thresholds were identified: an upper threshold of 0.129 J/cm2 and a lower threshold of 0.099 J/cm2. When the laser energy exceeded the upper threshold, ablation occurred under the laser‐energy‐dominated mode. When the laser energy fell between the upper and lower thresholds, ablation occurred under the cumulative‐effect‐dominated mode. The transition of ablation mode contributed to the diameter expansion and shape change. In addition, elemental composition varied significantly at the ablated crater and heat‐affected zone (HAZ), which were related to the degrees of reactions that occurred at different distances from the laser. Finally, surface hardness decreased from base material (32.52 GPa) to edge of crater (11.59 GPa) due to the escape of unpaired interstitial C atoms from the grain boundaries. [ABSTRACT FROM AUTHOR]

Ball milling is a key processing step in the manufacture of cemented carbide. That process is widely used at different scales: both industrial applications and laboratory experimentations. A bowl from the milling machine has however exploded during its use, leading to the destruction of the milling machine lid, the scattering of the powder that was milled, and a delay in the further experiments of the lab. The material to be milled was a mixture of high-entropy alloy aimed for use as a binder in tungsten carbide composite materials. The failure analysis study has been achieved with conventional methods such as x-ray diffraction, x-ray fluorescence, microstructures (by optical and scanning electron microscopies), and hardness testing. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to investigate qualitatively and quantitatively the elution of substances from polyester-urethane (Invisalign™) aligners and resin composite attachments (Tetric EvoFlow) in vivo. Methods: Patients (n = 11) treated with the aligners and attachments (16 per patient, without other composite restorations) for an average of 20 months, who were planned for attachment removed were enrolled in the study. Patients were instructed to rinse with 50 mL of distilled water upon entry and the rinsing solution was collected (before removal). Then, the attachments were removed with low-speed tungsten carbide burs for adhesive residue removal, a thorough water rinsing was performed immediately after the grinding process to discard grinding particle residues, and subsequently, after a second water-rinsing the solution was collected for analysis (after removal). The rinsing solutions were analyzed for targeted (LC-MS/MS: Bis-GMA, DCDMA, UDMA, BPA) and untargeted (LC-HRMS: screening of leached species and their degradation products) compounds. Results: Targeted analysis revealed a significant reduction in BPA after attachment removal (4 times lower). Bis-GMA, DCDMA, UDMA were below the detection limit before removal but were all detectable after removal with Bis-GMA and UDMA at quantifiable levels. Untargeted analysis reviled the presence of mono-methacrylate transformation products of Bis-GMA (Bis-GMA-M1) and UDMA (UDMA-M1), UDMA without methacrylate moieties (UDMA-M2), and 4-(dimethylamino) benzoic acid (DMAB), the degradation product of the photo-initiator ethyl-4-(dimethylamino) benzoate (EDMAB), all after attachment removal. Several amino acids and endogenous metabolites were also found both before and after removal. Conclusions: Elevated levels of BPA were traced instantaneously in patients treated with Invisalign™ and flowable resin composite attachments for the testing period. BPA was reduced after attachment removal, but residual monomers and resin degradation products were found after removal. Alternative resin formulations and attachment materials may be utilized to reduce eluents. [ABSTRACT FROM AUTHOR]

Joining high strength 2xxx series aluminum is known to be complex and difficult; these alloys are traditionally considered non-weldable for fusion welding. This paper describes details on welding AA2029-T8 for skin-stiffened structures using refill friction stir spot welding (RFSSW). RFSSW is a solid-state process invented in the early 2000s that produces spot welds that are strong, lightweight, flush, and hermetic. Cycle times between 1 and 3 s are discussed, and process forces within a range of 8 to 14 kN are demonstrated. Furthermore, lap-shear quasi-static tensile strengths are shown to be between 10 kN and 12 kN in 9 mm diameter spots. A comparison of the performance of RFSSW welds made with various tool materials—which include H13 tool steel, tungsten carbide, and MP159—is detailed. Comparisons of parameters, weld consolidation, and heat-affected zones are presented with discussion related to heat generation specific to each tool material. [ABSTRACT FROM AUTHOR]

Tungsten carbide (WC) and its composites are typically associated with high hardness and high wear resistance, posing challenges in conventional machining processes like turning. To address the machining difficulties of WC-Co, electrical discharge turning (EDT) was proposed. The rotational speed in EDT is a key factor influencing the machining results; however, conflicting reports exist about its impact on the EDT process. Therefore, the effect of rotational speed on three different machining regimes, including roughing, semi-finishing, and finishing, was investigated using energy-dispersive X-ray spectroscopy (EDX), SEM, and roughness tests. Additionally, elemental mapping was applied to illustrate the element distribution on the machined surface. The results indicated that increasing the rotational speed led to a 10% to 17% decrease in the recast layer thickness and a 14% to 54% reduction in the surface roughness (Ra). [ABSTRACT FROM AUTHOR]

Abstract—Experiments were carried out on the treatment of nanopowders of the W–C–Co system obtained by plasma-chemical synthesis in a microwave electromagnetic field with a frequency of 2.45 and 24 GHz in different gas media. The effect of treatment time, power input, and carbon content in the treated nanopowder on the yield of tungsten monocarbide WC was investigated. [ABSTRACT FROM AUTHOR]