Iron Covalent Doping in WB2 to Boost Hydrogen Evolution Activity

We report an iron covalent doping approach capable of effectively facilitating hydrogen evolution reaction (HER) activity of tungsten boride (WB2). The results demonstrated that the Fe-doped WB2 (Fe-WB2) can deliver...

Influence of tungsten compounds on reaction of 1-octene epoxidation by tert-butyl hydroperoxide and hydroperoxide decomposition

Catalytic ability of tungsten compounds in the reaction of hydroperoxide epoxidation of 1- octene and tert-butyl hydroperoxide decomposition was investigated. It is shown that the nature of ligand has significant effect on the catalytic activity of tungsten compounds in these reactions. It is established that boride and silicide of tungsten are the best choice for epoxidation reaction, whereas tungsten carbide exhibits poor activity. Tungsten boride is also the most active in the hydroxide decomposition reaction.

Investigation of Corrosion Resistance and Microstructural Performance of Zn-MgO-WB Composite Coating on Mild Steel

This Paper investigated the corrosion resistance and microstructural performance of zinc-magnesium oxide-tungsten boride (Zn-MgO-WB) composite coating on mild steel. Tungsten boride as an additive was co-deposited with zinc-magnesium oxide on mild steel via electrolytic deposition. The zinc-magnesium oxide and zinc-magnesium oxide-tungsten boride composite coatings were fabricated at the voltage of 0.6 and 0.8 V for 15 minutes and 45 °C. The effects of the deposits on the corrosion properties were examined. The corrosion behaviour was studied using linear polarization and weight loss method in 3.5% NaCl simulated environment. From the results obtained, it is evident that a decrease in applied potential influences the deposition of the coatings. The alloys with tungsten boride in their bath mixture performed better than those without. The zinc-magnesium oxide-tungsten boride (0.8 V) composite coated sample exhibits the least corrosion rate (Cr) of 0.0010482 mm/year and the microstructural examination of the sample via scanning electron microscope (SEM) unveiled homogeneous dispersion of particles and smooth morphology. The smooth morphology, defect-free surface, coupled with the uniform dispersion of the zinc-magnesium oxide-tungsten boride nanoparticles on the steel surface could have been responsible for high corrosion resistance performance of the coating in the simulated 3.5% NaCl medium. More so, the energy dispersive spectroscopy (EDS) revealed the presence of zinc, magnesium oxide, tungsten boride particles.

Bending Strength and Cutting Performance of WB-Coated-Diamond/Fe-Ni Composites

Diamond particle with tungsten boride (WB) coating was synthesized by the molten salt method. Three different diamond/Fe-Ni composites made from pristine diamond, B4C coated diamond and WB coated diamond with Fe-Ni powders were prepared by powder metallurgy. The composition and microstructure of the tungsten boride coating were investigated. Both bending strength and cutting performance of the composites were investigated. Addition of the WB coating provided an increased bending strength (871.2 MPa) and relative density (93.54%), compared with the composites consist of uncoated diamond and Fe-Ni (746.8 MPa, 92.81%). Three different Fe-Ni-based impregnated diamond drill bits contained 20 vol.% pristine diamond, B4C coated diamond and WB coated diamond were manufactured by powder metallurgy, respectively. Drilling rate of bits was measured by XY-4 geological core drill on granite. The test results show that the drilling rate of bits with WB coated diamond (2.42 m/h) was 40% higher than that with pristine uncoated diamond (1.72 m/h).

STUDY ON THE POSSIBILITY OF DOPING OF POWDER COMPOSITIONS FROM TUNGSTEN AND NICKEL BORIDE OBTAINED BY EXPLOSIVE PRESSING

The chemical composition of the phases obtained by explosive pressing in steel ampoules of tungsten boron and nickel powder compositions before and after heat treatment was studied. It has been established that it is possible by means of heat treatment at 1200 С to alloy with the material of the ampoule from austenitic steel 12Cr18Ni10Ti powder composition pressed by explosion, containing 50% tungsten boride.

Damage analysis of a perfect broadband absorber by a femtosecond laser

Plasmonic metamaterial absorbers are particularly important in different applications such as photodetectors, microbolometers and solar cells. In this paper, we propose a tungsten boride (WB, a refractory ceramic) based broadband metamaterial absorber whose optical properties is numerically analyzed and experimentally characterized. We have also analyzed the damage characteristics of this absorber using a femtosecond laser and compared with an ordinary Au metamaterial absorber. We observe that WB has almost the double absorption bandwidth with absorption more than 90% over the spectral range of 950 to 1400 nm when compared with the Au counterpart. Furthermore, we show that Au metamaterial is damaged at the power of around 36.4 mW whereas WB metamaterial is not damaged at that power (WB has high Tammann temperature than Au)-however the atom of WB material was knocked off by the bombardment of a femtosecond laser.