MIL-STD-1568 Materials And Processes For Corrosion Prevention And Control In Aerospace Weapons SystemsThis standard establishes the requirements for materials, processes and techniques, and identifies the tasks required to implement an effective corrosion prevention and control program during the conceptual, validation, development and production phases of aerospace weapons systems. The intent is to minimize life cycle cost due to corrosion and to obtain improved reliability.

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MIL-STD-1568C

5.2.3.5 Magnesium. Magnesium alloys shall be used only with specific approval of the procuring activity.

5.2.3.6 Beryllium. In applications where beryllium is an approval material, consideration shall be given to protective coatings to protect parts against corrosion. All beryllium shall be used in a passivated condition by a process approved by the procuring activity.

5.2.3.7 Mercury. Mercury and many compounds containing mercury can cause accelerated stress cracking of brass, aluminum and titanium alloys. Mercury shall not be used where spillage can contact these materials.

5.2.3.8 Depleted uranium. The general finish for depleted uranium shall be nickel plate to in accordance with the requirements of SAE AMS-QQ-N-290 or aluminum coated in accordance with the requirements of MIL-DTL-83488, plus one coat of MIL-PRF-23377 Type I primer, thickness 0.015 to 0.023 mm (0.0006 to 0.0009 inch).

5.2.4 Insulating blankets. Where thermal/acoustical insulating blankets are required, they shall be either procured with a permanent baked on water repellent binder system or protected with sealant to prevent any moisture absorbed by the blanket from contacting the metal structure. The blankets shall be attached to the aircraft frame members and contact with aircraft skins shall be avoided. Blankets shall be easily removable to facilitate maintenance and inspection.

5.3 Corrosion prevention during manufacturing operations. Precautions shall be taken during manufacturing operations to maintain the integrity of corrosion prevention requirements and to prevent the introduction of corrosion or corrosive elements.

5.3.1 Cleaning. Cleaning of various types of metallic surfaces, prior to application of the surface treatments and coatings, shall be as specified in MIL-DTL-5002, using materials and processes which have no damaging effect on the metal, including freedom from pits, intergranular attack and significant etching. After cleaning, all parts shall be completely free of corrosion products, scale, paint, grease, oil, flux, and other foreign materials, including other

metals, and shall be given the specific treatment immediately after cleaning. Particular care shall be exercised in the handling of parts to ensure that foreign metals are not inadvertently transferred, which may occur when steel is allowed to come into contact with zinc surfaces.

5.3.1.1 Titanium contamination. Care shall be taken to ensure that cleaning fluids and other chemicals are not used on titanium assemblies where entrapment can occur. Substances that are known to be contaminants and can produce stress corrosion cracking include:

a. Hydrochloric acid

b. Trichloroethylene/Trichloroethane c. Carbon tetrachloride

d. All chlorides