Production of fine calcium powders by centrifugal atomization with rotating quench bath

Journal Article · Mon Feb 08 00:00:00 EST 2016 · Powder Technology

DOI:https://doi.org/10.1016/j.powtec.2016.12.011· OSTI ID:1342925

Tian, Liang ^[1]; Anderson, Iver ^[1]; Riedemann, Trevor ^[1]; Russell, Alan ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

Recently, a novel Al/Ca composite was produced by severe plastic deformation of Al powders and Ca granules for possible use as a high-voltage power transmission conductor. Since the strength of such composites is inversely proportional to the Ca filament size, fine Ca powders (less than ~250 μm) are needed to achieve the desired high strength for the powder metallurgy production of an Al-matrix composite reinforced by nano-scale Ca filaments. However, fine Ca powders are not commercially available. Therefore, we have developed a method to produce fine Ca powders via centrifugal atomization to supply Ca powder for prototype development of Al/Ca composite conductor. A secondary goal of the project was to demonstrate that Ca powder can be safely prepared, stored, and handled and could potentially be scaled for commercial production. Our results showed that centrifugal atomization can yield as much as 83 vol. % Ca powder particles smaller than 250 μm. The mean particle size sometimes matches, sometimes deviates substantially from the predictions of the Champagne & Anger equation likely due to unexpected secondary atomization. The particle size distribution is typical for a ligament-disintegration atomization mode. Scanning electron micrographs showed that the morphology of these Ca powders varied with powder size. Spark testing and auto-ignition tests indicated that the atomized powders were difficult to ignite, providing confidence that this material can be handled safely in air.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Electricity (OE)
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 1342925
• Alternate ID(s): OSTI ID: 1416753
• Report Number(s): IS-J-9156; PII: S0032591016308816
• Journal Information: Powder Technology, Vol. 308, Issue C; ISSN 0032-5910
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Calcium
Centrifugal atomization
Powder
Stability
particle size
particle morphology