Accession Number:

ADA247932

Title:

Microcalorimetric Study of the Aging Reactions of Atomized Magnesium Powder

Descriptive Note:

Interim rept. Oct 1990-Sep 1991

Corporate Author:

NAVAL SURFACE WARFARE CENTER CRANE DIV IN

Personal Author(s):

• Shortridge, Robert G.
• Chin, Aton
• Hubble, Bill R.

Report Date:

1992-02-20

Pagination or Media Count:

22.0

Abstract:

Magnesium powder is used widely as a fuel in pyrotechnic compositions, e.g., in illuminating flare formulations. Powdered magnesium chemically is a very reactive metal and it is prone to undergo relatively slow surface reactions at room temperature with moist air. In this study the technique of microcalorimetry has been used to characterize these undesired magnesium degradation reactions. Experiments have been carried out using large magnesium samples to simulate a storage environment and small magnesium samples to simulate the magnesium powder in a pyrotechnic production line environment. Powdered magnesium can react with both water vapor and oxygen found in air with the reaction with water vapor being at least an order of magnitude more rapid. The degradation reactions are relatively slow, e.g., at 70 deg C and 100 relative humidity 1 magnesium degradation requires approximately 15 hours reaction time. However, a 1 degradation of the powdered magnesium translates into as much as 8 decrease in the burn rate of a pyrotechnic composition which incorporates the degraded magnesium.

Descriptors:

• *MAGNESIUM
• METALS
• ENVIRONMENTS
• PRODUCTION
• AGING(MATERIALS)
• DEGRADATION
• AIR
• POWDERS
• REACTIVITIES
• ROOM TEMPERATURE
• OXYGEN
• FUELS
• SAMPLING
• SURFACE REACTIONS
• STORAGE
• BURNING RATE
• COMPOSITION(PROPERTY)
• HUMIDITY
• WATER VAPOR
• PYROTECHNICS
• MICROCALORIMETRY

Subject Categories:

• Inorganic Chemistry
• Metallurgy and Metallography
• Pyrotechnics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE