Properties of High-Energy Ball-Milled and Hot Pressed Nanocrystalline Tantalum

Abstract

The paper describes the process of high-energy ball
milling of tantalum microcrystalline particles aiming at achieving
a nanocrystalline material. During intense milling, a reduction of
the crystallite size occurs, which is the consequence of strong
plastic deformation, the introduction of dislocations and the
formation of subgrains. Due to the plastic nature of the powders,
the particle size increases at the initial stage of milling, where
cold welding and plastic deformation of the particles takes place.
Due to the strain hardening, however, the particles crush into
smaller ones. The nanocrystalline powders were hot pressed. The
bulk hot pressed nanocrystalline tantalum have hardness as high
as 1067 HV and useful corrosion resistance in chloride
electrolyte.