Powder metallurgy (PM) and additive manufacturing (AM) are rapidly growing industries that rely heavily on the production of high-quality metal powders. Powders intended for PM and AM require high degrees of sphericity, homogeneous distributions of their constituent elements, absence of satellite particles and desirable particle sizes. Atomization of molten metal is the key step in the process of production of metal powders. The process involves breaking down molten metal into fine, spherical particles through a high-velocity gas stream.
Experimental setup
Gas-assisted atomization (hereafter termed “gas atomization”) of a liquid jet into a spray of small droplets is commonly used in many industrial applications ranging from combustion processes, agriculture, medical therapies, and powder fabrication, among others. The breakup of the liquid jet is the result of a series of instabilities. Shear-induced Kelvin-Helmholtz (KH) instabilities give rise to liquid undulations, and once their crests destabilize through Raleigh-type instabilities, they are stretched into ligaments by the fast gas flow and fragment into small droplets under the influence of capillary forces and gas Reynolds stresses. The final spray properties that are of interest include the droplet size and velocity distributions, as well as the number of droplets per unit volume and their spatial distribution.
The present research is aimed to measure the primary breakup process in close-coupled gas atomization (CCGA) of a liquid jet by a high-speed gas flow.
(Left) Hologram; (right) Reconstructed hologram
Students working on the project:
Tiansong Cheng (PhD) co-advised by Prof. Bo Kong (Guangdong – Technion Israel Institute of Technology
Ron Leibovici (MSc)