Steel composites reinforced with alumina nanoparticles were prepared by powder metallurgy process. Samples containing two different amounts of carbon (0.35 and 0.55 wt.%) and 0-5 wt.% Al2O3 nanoparticles were fabricated by mixing, compacting and sintering of diffusion bonded Distaloy AE powder. The density, hardness and wear tests were performed on the prepared samples. Fu...

Alumina-based nanocomposites reinforced with niobium and/or carbon nanotubes (CNT) were fabricated by advanced powder processing techniques and consolidated by spark plasma sintering. Raman spectroscopy revealed that single-walled carbon nanotubes (SWCNT) begin to break down at sintering temperatures >1150 C. Nuclear magnetic resonance showed that, although thermodynamically unlikely, no Al4C3 ...

Al–Mg alloy powder was cryomilled to achieve a nanocrystalline (NC) structure having an average grain size of 50 nm with high thermal stability, and then consolidated by quasi-isostatic forging. The consolidation resulted in a bulk material with ultrafine grains of about 250 nm, and the material exhibited enhanced strength compared to conventionally processed Al–Mg alloy. The hardness of as-cry...

(Dated: February 1, 2008) A normal-fluid component varying as T is observed at very low temperatures in superfluid He and He-He mixture films adsorbed in alumina powder. The normal fluid appears to arise from thermally excited third sound that has one-dimensional propagation characteristics. A Landau model of third sound excitations in an infinite cylindrical pore by Saam and Cole provides good...

his study used quantitative image analysis to examine the effect of powder forming method on a population of dense heterogeneities that could e imaged in partially sintered alumina using optical microscopy. Powder pressing resulted in a higher area fraction of dense heterogeneities than lip casting. Extreme value analysis was used to predict the size of the largest heterogeneity in the populati...

Al 5083 alloy powder was mechanically milled in liquid nitrogen to achieve a nanocrystalline (NC) structure having an average grain size of 50 nm with high thermal stability, and then consolidated by quasi-isostatic (QI) forging. The consolidation resulted in ultrafine grains (UFG) of about 250 nm, and the bulk material exhibited enhanced strength compared to conventionally processed Al 5083. T...

Nanocrystalline cobalt oxide material has been successfully synthesized via ultrasonicationprecipitation method. The obtained material shows the cubic phase and spherical size agglomerated morphology as confirmed by the powder X-ray diffraction and scanning electron microscopy measurement. The electrochemical performance of the modified electrode has been analyzed systematically. The electrode ...