Tetsu-to-Hagane
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
Particle Size of Atomized Alloy Powder Prepared by Using a Confined-type Atomizing Nozzle
Tadashi FUKUDAKazutaka ASABE
Author information
JOURNAL FREE ACCESS

1999 Volume 85 Issue 9 Pages 703-709

Details
Abstract

The influences of the gas jet spouted from the atomizing nozzles, gas and metal flow rate ratio and gas pressure on the median diameter and particle size distribution were investigated. The median diameter of atomized powder varies in proportion to the square root of Ml/Mg value when the atomized powder was formed at various melt or gas flow rate under the same other conditions. The median diameter varies inversely proportional to the mean gas velocity when the powder was atomized using various atomizing nozzles which have different dimension i.e. the apex angle and gas jet nozzle configuration. Approximately the same median diameter powder was obtained at the same gas flow rate regardless of the gas jet pressure. An experimental formula was obtained as follows;
d50p/Dl=63.6√(Ml/Mg)·(σl/(Dl·ρl·V2g))·(vl/vg)
where, d50p: Median diameter of atomized powder (m), Dl: Diameter of melt delivery tube (m), Ml: Mass flow rate of molten metal (kg/s), Mg: Mass flow rate of atomizing gas (kg/s), σl: Surface tension of molten metal (N/m), ρl: Density of molten metal (kg/m3), Vg: Gas velocity (m/s), vl: Kinematic viscosity of molten metal (m2/s), vg: Kinematic viscosity of atomizing gas (m2/s). The fraction of coarse powder increased when the atomization was performed with a concave gas velocity distribution compared to a convex one which is the ordinary case. The calculated particle size distribution coincides roughly with the experimental results. It was shown that the particle size distribution depends on the gas velocity distribution.

Content from these authors
© The Iron and Steel Institute of Japan
Previous article
feedback
Top