Space Materials and Surface Treatment Guide

For details on low outgassing materials see Vacuum

Aluminum

Bare aluminum needs to be protected to prevent corrosion in space and on the ground during handling, storage (near the ocean particularly), and in orbit. Hard anodizing is also used to prevent cold welding of deployables (see CubeSat Design Specification).

Anodizing:

Inorganic type III black anodizing is suitable for vacuum and space applications where a typical black coating is required. For a detailed procedure, see ESA standard Black-anodizing of metals with inorganic dyes, ECSS-Q-ST-70-03C.

Use of Type III anodize or paint instead of Type II anodization is recommended on series 2000 and 7000 aluminum.

https://llis.nasa.gov/lesson/8403

Relevant JSC Structural Engineering Division Process Specification:

• PRC-5006 Anodizing of Aluminum Alloys

• PRC-5008 Specialty Anodizing of Aluminum Alloys to Control Optical Properties

Further reading:

• Goueffon, Y., Arurault, L., Mabru, C., Tonon, C., & Guigue, P. (2009). Black anodic coatings for space applications: Study of the process parameters, characteristics and mechanical properties. Journal of Materials Processing Technology, 209(11), 5145-5151.

• Persky, M. J. (1999). Review of black surfaces for space-borne infrared systems. Review of Scientific Instruments, 70(5), 2193-2217.

Conversion coating

Chromate conversion coating (“Alodining”) is recommended on flight hardware to prevent corrosion and short circuits.

• PRC-5005 Chemical Conversion Coating of Aluminum Alloys

Titanium

Titanium can generally be untreat except when subject to wear per NASA-STD-6016C:

All regions of titanium alloys for spaceflight hardware that provides mission-critical functions that are subject to fretting or wear shall be anodized per SAE AMS2488D, Anodic Treatment - Titanium and Titanium Alloys Solution, pH 13 or Higher, or hard-coated utilizing avwear-resistance material, such as tungsten carbide/cobalt thermal spray.

Steel

Relevant JSC Structural Engineering Division Process Specification:

• PRC-5002 Passivation of Corrosion-Resistant Steel

• PRC-5007 Electroless Nickel Plating

• PRC-5009 Electropolishing of Corrosion-Resistant Steel