  With the introduction of micro and nanosensors and devices, the need for pure
metal and ceramic powders have risen. Spherical pure metal powders and their
alloys are vital raw materials for near-net-shape fabrication via
powder-metallurgy manufacturing routes as well as feed stocks for powder
injection molding, and additive manufacturing. Employing atomization processes
to achieve spherical powders dates back to 1980s and different attitudes to
maintain a plasma current have been developed including gas atomization, plasma
atomization, plasma-rotating-electrode atomization, and freefall atomization.
Facilities for employing the aforementioned methods have always been expensive.
This paper proposes two new processes by which pure spherical powder is
achievable with relatively low costs. The first method proposed will deal with
attrition of coarse particles in cryogenic milieu via coinciding jets (i.e.,
cryogenic coinciding jets or CCJ), while the second proposed method concerns
melting and evaporation of metals caused by the heat emitted from a plasma
channel made by the electric field breakdown at micrometer separations of
metallic electrodes (entitled as electrode-plasma-atomization method or EPA).
The CCJ method may face challenges such as cold welding of particles due to
high speed collision and inefficiency of process because of presence of high
plastic deformation and coldworking, whereas the EPA method demands only the
use of electrically conductive materials as electrodes. Titanium powder with
the particle average sizes of 62nm and also 300-400nm was achieved via the EPA
method. Studies also suggest that the CCJ method is expected to produce
Titanium nanopowder with less than %0.05wt contamination.
