Surface contamination and corrosion in pyrotechnic actuators

Conference · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6392640

Jungst, R G; Quinn, R K; Massis, T M; Roberts, R N; Whan, R E

Accelerated aging studies of pyrotechnic actuators containing a mixture of titanium and potassium perchlorate powders have revealed that extensive corrosion of the metal pins and bridgewires used to ignite the device occurs in relatively short times. Analyses show that the corrosive process is associated with chlorine and organic contaminants, the primary sources of which are residual cutting oils, chlorinated cleaning solvents, and chlorine-bearing adhesives. These can trigger corrosion by attacking the passivating oxide layer on the surface of metal alloys, thereby promoting reaction between the pyrotechnic and the metal. The contaminants may also react directly with the pyrotechnic to cause decomposition to corrosive species. Residual moisture in the pyrotechnic powder tends to enhance corrosion rates when contaminants are present. Tests run on several metal alloys have verified the corrosive action of certain organic solvent mixtures. Specifically, Tophet A, Tophet C, and Alloy 52 were corroded when exposed to combinations of alcohols and chlorinated organic liquids. Individual solvents did not cause corrosion. In each case, Tophet C which contains about 25% iron was attacked faster than Tophet A which is iron free. The gas phase in equilibrium with a boiling solvent mixture was more corrosive than the hot liquids or hot gases alone. In order to eliminate this corrosion problem, some materials of construction in the actuator have been changed and a new cleaning procedure based on non-chlorinated solvents and boiling hydrogen peroxide has been incorporated into the production process. This treatment is effective as demonstrated both by analysis of component surfaces and by additional aging studies on cleaned units.

• Research Organization: Sandia Labs., Albuquerque, NM (USA)
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 6392640
• Report Number(s): SAND-78-0573C; CONF-780907-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360604* -- Materials-- Corrosion
Erosion
& Degradation
ALKALI METAL COMPOUNDS
CHEMICAL REACTIONS
CHLORINE
CHLORINE COMPOUNDS
CORROSION
CORROSIVE EFFECTS
ELEMENTS
HALOGEN COMPOUNDS
HALOGENS
NONMETALS
OXYGEN COMPOUNDS
PERCHLORATES
POTASSIUM COMPOUNDS
POTASSIUM PERCHLORATES
POWDERS
PYROTECHNIC DEVICES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS