Dense, uniform, and adherent chemically vapor-deposited mullite coatings were deposited on SiC substrates using the AlCl3–SiCl4–H2–CO2 system. Typical coating morphology consisted of a thin interfacial layer of g–Al2O3 nanocrystallites embedded within a vitreous SiO2-based matrix. When a critical Al/Si ratio of 3.2 ± 0.29 was reached within this nanocrystalline layer, mullite crystals nucleated...

At the beginning of the present century it has been demonstrated that nanocrystalline titanium (NC-Ti) can be fabricated by hydrostatic extrusion (HE) which is one of the severe plastic deformation method. NC-Ti obtained in such a way exhibited excellent mechanical properties. The influence of HE on the microstructure and mechanical properties of titanium Grade 2 was first analyzed in 2005. In ...

The properties of plasma sprayed Y-Ba-Cu-O coatings deposited on metallic substrates are studied. Stainless steel, nickel steels and pure nickel are used as substrate. Y-Ba-Cu-O deposited on stainless steel and nickel steel reacts with the substrate. This interaction can be suppressed by using an yttria-stabilized zirconia (YsZ) diffusion barrier. However, after heat treatment the Y-Ba-Cu-O lay...

A series of nickel sulfide nanocrystallines with hierarchical structures was successfully fabricated in situ on a nickel substrate. The nanocrystalline materials with three dimensional (3D) structures were synthesized via self-assembly under moderate conditions, with ethylenediamine and ethylene glycol as the mixed solvents. The structure and morphology of each nickel sulfide could be controlle...

Although amorphous structures have been widely obtained in various multi-component metallic alloys, amorphization in pure metals has seldom been observed and remains a long-standing scientific curiosity and technological interest. Here we present experimental evidence of localized solid-state amorphization in bulk nanocrystalline nickel introduced by quasi-static compression at room temperature...

Short cracks, extending to the interdiffusion zone, have been observed in platinum-modified nickel-aluminide diffusion coatings on single-crystal CMSX-4 superalloys after these have been subject to short (10 min) rapid thermal cycles. The cracks were revealed after removing the thermally grown oxide formed during cycling on the coating surfaces. Cracking was observed for coatings subject to the...

ron phosphate coatings have found a wide range of use in the metalI finishing industry as a convenient method for achieving reasonably high levels of corrosion resistance. Flexibility of processing parameters and ease of use are probably the biggest reasons that iron phosphating enjoys its continued popularity. The corrosion resistance of iron phosphate coatings can be dramatically improved by ...

Reactively sputtered nickel oxide (NiOx) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O2(g). These NiOx coatings provide protective layers on a variety of technologically important semiconducting photoanodes, including textured crystalline Si passivated by amorphous silic...