Features of /spl beta//spl rarr//spl alpha/ transformation in electroexplosive tungsten nanopowders

摘要

X-ray investigations of tungsten nanopowder produced with wire electrical explosion (WEE) have been carried out. It was found that two polymorph phases, /spl alpha/-W and /spl beta/-W, are simultaneously present in the nanopowder. During annealing in argon, /spl beta/-phase is first amorphised and then disappears. In contrast to /spl alpha/-phase which does not practically differ from that of standard material, /spl beta/-W is characterized with microdeformations of the lattice (increased lattice parameter). It is assumed that it is a kind of excess energy storage in nanoparticles of electroexplosive tungsten.