The ball milling of powders is a non-equilibrium technique (similar to rapid solidification processes) that can be used for production and structural modification of materials. Carbon nanotubes (CNTs) are relatively new materials with excellent combination of properties. They are one of the advanced reinforcement materials for engineering composites. Besides the polymer and ceramic matrices, in...

Rapid solidification by planar flow casting has been found to have introduced deficiencies, viz. partial crystallinity, air pockets and compositional difference in the ribbons of rapidly solidified Ti42⋅9Cu57⋅1 alloy. In order to investigate the effects of these deficiencies on the corrosion of rapidly solidified Ti42⋅9Cu57⋅1 alloy ribbons, electrochemical behaviour of alloy ribbons has been in...

Silicon nano-wires were fabricated using thin Silicon on Insulator (SOI) wafers and a combination of anisotropic wet etching by TetraMethyl Ammonium Hydroxide (TMAH) and Local Oxidation of Silicon (LOCOS). These nano-wires were submitted to laser exposure using gas immersion laser doping (GILD). The result was the formation of either periodic nano-structures or silicon balls. Since the process ...

Very fine (d < 10/~m) metal and alloy powders can be produced efficiently by a high pressure gas atomization (HPGA) technique. Rapid solidification processing, metal injection molding, thermal spraying and other emerging powder-processing approaches benefit from the use of such fine powders. This paper reports on the results of an investigation of gas atomization process dynamics with emphasis ...

The microstructure of melt extracted Ti-44Al-8Nb-0.2W-0.2B-1.5Si fiber were investigated. When the rotation speed increased from 2000 to 2600 r/min, the appearance of the wire was uniform with no Rayleigh-wave default. The structure was mainly composed of fine α₂ (α) phase dendritic crystal and a second phase between dendrite arms and grain boundaries. The precipitated second phases were confir...

Rapid solidification experiments have been performed on an Ni-25.3 at.% Si alloy using drop tube techniques. The dominant phase formed is found to be Ni25Si9, with Ni31Si12 and く1-Ni3Si also being present. SEM and TEM analysis revealed a novel eutectic structure consisting of lamellar of metastable Ni25Si9 and く1-Ni3Si, the width of these being around 200 nm and 20 nm respectively. This result ...

A solidification processing approach to the refinement of lead-tellurium-antimony alloy microstructure is described. Liquid alloys with eutectic, hyper-eutectic and hypo-eutectic compositions (relative to lead) were cooled to the solid state in three distinct ways, i.e. by water quenching, air cooling and furnace cooling. The structures of the alloys resulting from the three different solidific...