The response to cycling contact fatigue load of a WC-6%Co carbide coated with Ti(C,N)/α-Al2O3 CVD multilayer was investigated in dry and wet conditions. Imprints conditions were characterized by small thin cracks forming circumference at the maximum radii imprint. damaged coating totally present final imprint test. Wet indentations showcase an area where α-Al2O3 layer has been removed throughou...

A series of bulk oxides (Sb2O3, Sb2O4, VSbO4, and V2O5) and alumina-supported oxides (Sb-O, V-O, and Sb-V-O) were synthesized by conventional methods. The resulting catalysts were characterized with XRD, BET, Raman, and CH3OH-temperature programmed surface reaction (TPSR) spectroscopy. XRD and Raman spectroscopy confirmed that the bulk oxides are present as crystalline phases and the alumina-su...

Aluminium oxide (Al2O3), commonly known as alumina, is a widespread naturally occurring compound that has a broad range of industrial applications. Besides its use as a pigment or abrasive, alumina also plays a vital role as catalyst support for desulfurization or hydrogenation reactions. In the latter case, the active phase on the catalyst often consists of nickel metal nanoparticles. The inte...

the potential of carbon nanotubes (cnt) supported cobalt catalysts for fischer-tropsch (ft) reaction is shown. using the wet impregnation method cobalt on carbon nanotubes catalysts were prepared with cobalt loading varying from 15 to 45 wt. %. the catalysts are characterized by different methods including: bet physisorption, x-ray diffraction, hydrogen chemisorption, and temperature-programmed...

Alumina-supported manganese catalysts with cryptomelane and/or birnessite structure have been prepared using a simple method based on the thermal decomposition of potassium permanganate. The samples have been characterized by XRD, FTIR, TGA, DSC, N2 adsorption at −196 °C, SEM, H2-TPR and XPS, and their catalytic activity for soot combustion has been tested and compared to that of a reference Pt...

It is acknowledged that cellular responses are highly affected by biomaterial porosity. The investigation of this effect is important for the development of implanted biomaterials that integrate with bone tissue. Zirconia and alumina ceramics exhibit outstanding mechanical properties and are among the most popular implant materials used in orthopedics, but few data exist regarding the effect of...

We employ a combination of Z-contrast scanning transmission electron microscopy (ZSTEM) and first-principles density-functional calculations to investigate the interaction between metal atoms and cubic alumina catalytic supports. We show that there are two observed La sites at the porous γalumina surface, and that single La atoms do not exhibit a tendency to cluster. Cr behaves very differently...

The work was aimed at the investigation of kinetics Spark Plasma Sintering (SPS) α-Al2O3 particles with amorphous surface layers and effect on grain growth mechanical properties alumina. objects investigations comprised:(i) submicron powder, (ii) powder particles' surfaces, (iii) fine-grained powder. powders (i) were used to analyze sintering kinetics. Powders initial particle sizes shrinkage t...

Quasi-static and dynamic damage mechanisms in alumina tiles were investigated. The tiles were under a variety of boundary conditions at the tile's edges during impact NATO 0.3 cal. AP rounds with hardened and sharpened steel core were used. The alumina tile samples were 50x50 mm2 area, the thicknesses ranging from 5 to 12 mm. 'he tiles were mounted in a special confinement frame, which enabled ...

Quasi-static and dynamic damage mechanisms in alumina tiles were investigated. The tiles were under a variety of boundary conditions at the tile's edges during impact NATO 0.3 cal. AP rounds with hardened and sharpened steel core were used. The alumina tile samples were 50x50 mm2 area, the thicknesses ranging from 5 to 12 mm. 'he tiles were mounted in a special confinement frame, which enabled ...