Transition metal carbides have been utilized as an alternative catalyst to expensive noble metals for the conversion of biomass. Tungsten and molybdenum carbides have been shown to be effective catalysts for hydrogenation, hydrodeoxygenation and isomerization reactions. The satisfactory activities of these metal carbides and their low costs, compared with noble metals, make them appealing alter...

The present work adresses the evaluation of modified 9Cr-1Mo steels magneic hystersis loop and magnetic Barkhsuen emission techniques for the samples subjected to high temperature ageing for different durations. The initially quenched and then tempered material revealed different magnetic behaiour with ageing. The relxation of stresses and reduction of high value of dislocations due to quenchin...

The effect of coherency WC/Co phase boundaries on the fracture toughness of the nanocrystalline WC-Co cemented carbides is studied by MD simulation method. The simulation results show that the nanocrystalline WC-Co cemented carbides with coherency WC/Co phase boundaries has higher fracture toughness than that without coherency WC/Co phase boundaries. Moreover, the mechanism of why coherency WC/...

The electronic structure of the ground state of monoxides MO and carbides MC2 with M an alkaline-earthmetal atom (Be to Ba) has been investigated. Bond energies, vibrational frequencies, dipole moments and equilibrium bond lengths have been calculated using a hybrid density functional method. To understand the bonding characteristics, the ELF (electron localization function) and the NBO (natura...

Hastelloy X (HX) is a Ni-based superalloy which suffers from high crack susceptibility during the laser powder bed fusion (LPBF) process. In this work, the microstructure of as-built HX samples was rigorously investigated to understand the main mechanisms leading to crack formation. The microstructural features of as-built HX samples consisted of very fine dendrite architectures with dimensions...

Work during 1963 is reported and the work from mid-1960 reviewed on a comprehensive program of thermodynamic and kinetic studies necessary to the theoretical consideration to temperatures of 3000K of the reactions of the zirconium and hafnium carbides and borides with oxygenor halogen-containing atmospheres. ; • Work presented includes: preparation of borides and carbides; low ', temperature he...

The 25Cr-35Ni heat resistant steel has been widely used when resistance to oxidation and creep rapture at elevated temperatures is required. In this paper, the microstructural effect on the weldability of this alloy is investigated. The results of this study indicate that this steel has a perfect weldability in the as cast condition but does not possess good weldability in the aged condition. T...

A long-standing challenge in physics is to understand why cementite is the predominant carbide in steel. Here we show that the prevalent formation of cementite can be explained only by considering its stability at elevated temperature. A systematic highly accurate quantum mechanical study was conducted on the stability of binary iron carbides. The calculations show that all the iron carbides ar...

The thermal-stress resistance and fracture-strength behavior of TIC and WC after severe thermal shocking were investigated. The damage-resistance parameter, (K1c/af)2, for both carbides was determined over a wide range of loading rates and temperatures. The fracture-strength behavior of these two carbides in the quenching temperature range of 25" to 800°C follows Hasselman's model for an instan...

After WW2, a huge market opened in the growing economies and cemented carbides contributed as tool materials and construction parts to their industrial development. Today, cemented carbides are the workhorses in all areas of the manufacturing industries: no factory without cemented carbide tools; no production of glass bottles, aluminium cans or plastic tubes which has not benefited from these ...