Plasma Chemical Synthesis of Aluminum Nitride Nanopowder

We studied in detail the process of producing nanosized aluminum nitride using inductively coupled nitrogen plasma from micron powder of pure aluminum. The phase and granulometric composition of the obtained nanopowders, as well as their morphology, was studied. The influence of various parameters (initial components, gas flow rates, feed rate of the initial powder, etc.) on the synthesis result is determined. Received nanodispersed Al-AlN powder with particle sizes up to 300 nm and aluminum nitride content from 11.6 to 48.8%.

Synthesis and Magnetic Properties of Ni and Carbon Coated Ni by Levitational Gas Condensation (LGC)

The nickel (Ni), and carbon coated nickel (Ni@C) nanoparticles were synthesized by levitaional gas condensation (LGC) methods using a micron powder feeding (MPF) system. Both metal and carbon coated metal nano powders include a magnetic ordered phase. The synthesis by LGC yields spherical particles with a large coercivity. The abnormal initial magnetization curve for Ni indicates a non-collinear magnetic structure between the core and surface layer of the particles. The carbon coated particles had a core structure diameter at and below 10 nm and were covered by 2-3 nm thin carbon layers. The hysteresis loop of the as-prepared Ni@Cs materials with unsaturated magnetization shows a superparamagnetic state at room temperature.

Characterization and Sintering Behaviors of Fe Based Nanopowders Prepared by Arc Discharge Process

The formation of Fe nanopowders by Plasma Arc discharge process and sintering behavior of Fe nanopowder has been investigated. The effect of processing parameters on the size and microstructure and their pressureless sintering behaviors have been analyzed. Also the addition effect of micron powder to nanopowder on the compaction and sintering was studied. The prepared Fe nanpowder showed nearly spherical shape with the average size of 100 nm. The surface oxide layer of nanopowder played an important role on the initial densification of the green compact. The hardness and sintered density of nano/micron bimodal powder was similar to those of pure nanopowder.