Synthesis and dynamic compaction of ceramic nano powders by techniques based on electric pulsed power

Abstract

Studies on the production of nanometer-sized powders by the exploding wire method were conducted. The aim of the work was to attain a particle distribution with a high yield of particles below 20 nm in size. Powders of alumina and titania were generated during the experiments by maintaining a definite partial pressure of oxygen inside the explosion chamber. The particles are spherical in shape with specific surfaces up to 100 m2/g. The output capacity is on the order of 1 kg/h with an energy consumption of 2 kWh/kg. Alumina powders crystallize in the gamma and delta structures, titania powders consist of anatase and rutile. The second part of the studies deals with the compaction of nano-sized powders by application of pulsed electro-magnetic power. For the compaction of nano-sized Al2O3 powder pressure pulses in the range from 1 GPa to 5 GPa, lasting 3 - 300 μs, were applied. The simply shaped bulk samples maintained a nano-crystalline structure and reached 62 to 83 % of the theoretical density. © 1995.