Hermetic sealing corrosion tests

Leak tests Hermetic seal tests MIL-STD-883 method 1014 JIS C 7022 A-6 lEC PUB 68 Test Q [Pressure cooker test (PCT) to evaluate moisture resistance in a short period of time EIAJ IC-121 18] Final seal Performance degradation, shorts or opens caused by chemical corrosion or moisture, intermittents... 

Transportation of military equipment in unpressurized aircraft exposes hardware to a low-pressure environment that it was not designed to withstand. Low-pressure tests are therefore conducted on assembled equipment to check for pressure leaks, fluid leaks, evaporation of lubricants, failure of hermetic seals, etc. These types of failures may or may not lead to corrosion problems, but they certainly will lead to erratic operation or malfunction, or both. Missiles and space equipment are required to op>erate in low-pressure environments however, low-pressure tests have caused sparks and corona that did not (or would not) show up at a lower altitude or higher-pressure environment. The tests are conducted by lowering the pressure in the chamber, allowing the equipment to outgas and come to equilibrium before it is operated. The conditions usually are optimized at ambient temperatures and the low pressures held for at least an hour. The equipment then may be operated either at low pressure or returned to ambient pressure and then operated. 

TITANIUM. Ti. In laboratory tests, titanium was found to cause corrosion of contacting aluminum alloys in high chloride-containing envimiments by gah anic action. Hermetically sealed aluminum alloy... 

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