A Study of Liquid Metal Atomization Using Close-Coupled Nozzles, Part 2: Atomization Behavior

Published

January 24, 2005

Author(s)

Steven P. Mates, G S. Settles

Abstract

In this paper we examine the gas dynamic and atomization behavior of a convergent and a converging-diverging (c-d) close-coupled nozzleused to fabricate fine metal powders by gas atomization. Part 1 of this paper characterized and compared the gas dynamic behavior of the two nozzles over a range of nozzle pressure ratios (stagnation pressures). Part 2 focuses on the atomization behavior of the nozzles. A high-speed schlieren technique is used to visualize the liquid breakup behavior and the supersonic gas flow pattern in which it occurs. Our results indicate that the atomization process examined here does not follow previously proposed models. Rather than being dominated by primary breakup of a melt film, this process involves secondary breakup over an extended distance from the nozzle. The particle size distribution appears influenced by a balance between velocity decay and secondary breakup length scales that is physically reltaed to the gas-to-metal mass flux ratio. Finally, the c-d nozzle did not outperform the convergent nozzle over most of the range examined.

Citation

Journal of Atomization and Sprays

Volume

15

Pub Type

Journals

Keywords

gas atomization, metal powder, particle size distribution, powder metallurgy

Citation

Mates, S. and Settles, G. (2005), A Study of Liquid Metal Atomization Using Close-Coupled Nozzles, Part 2: Atomization Behavior, Journal of Atomization and Sprays (Accessed September 26, 2023)