DefinePK

Abstract

Nb-16Si (at. %) powder alloy was prepared by mechanical alloying (MA) in a planetary ball mill (Fritsch Pulverisette-4) from pure elemental powders. For the process of Nb-16Si powder spheroidization an experimental plasma generator based on thermal plasma arc generator with vortex discharge stabilization was used. Experimental results show that Nb-16Si spherical powder with a high degree of spheronization using starting powder fractions of +45-71 µm and +71- 100 µm can be prepared in a stream of argon thermal plasma with hydrogen additives generated in plasmatron. It is shown that the main peaks in the X-ray graph after MA correspond to a solid solution of niobium with a cubic lattice and the parameter a = 0.333 nm, as well as niobium silicide Nb5Si3 with a hexagonal lattice (P63/m) a = 0.7536 nm and c = 0.5249 nm. After spheroidization the hexagonal lattice of niobium silicide Nb5Si3 is transformed into a tetragonal lattice (I4/m) with the parameter a = 0.6557 nm and c = 1.186 nm. The other phase components remain unchanged.