Nano-sized particles formed by pulsed discharge of powders

Exploding wire and pulsed wire discharge are effective methods to form nano-sized particles. They are based on evaporation of thin metal wires by applied large electric current as the principle to form particles. Many kinds of wires have been used to form nano-sized particles so far. However, materials which are not sufficiently ductile to form thin wires are unsuitable for the methods. We have developed a method for powders to be held between electrodes by using heat-shrinkable tubes and discharged for evaporation. Nano-sized intermetallic NiAl compound particles were synthesized from mixed powders of Al and Ni. Si powder could be discharged by sealing with a thin Al wire, and nano-sized Si particles were formed. Utilizing this technique, various metal powders can be used for raw materials in pulsed discharge.

► We have developed a method to form nano-sized particles by evaporation of powders.
► Powders were held between electrodes by using heat-shrinkable tubes and discharged.
► Nano-sized NiAl compound particles were synthesized from mixed powders of Al and Ni.
► Nano-sized Si particles were formed by sealing with a thin Al wire and discharging.