Active Standard ASTM B879 | Developed by Subcommittee: B08.07
Book of Standards Volume: 02.05
Historical (view previous versions of standard)
Significance and Use
3.1 The processes described in this practice clean and provide a paint base for the finishing of magnesium and magnesium alloys. Service conditions will determine, to some degree, the specific process to be applied.
1.1 This practice covers a guide for metal finishers to clean and then provide a paint base for the finishing of magnesium and magnesium alloys using chemical conversion coatings. Where applicable (for example, aerospace) secondary supplementary coatings (for example, surface sealing) can be used (see Appendix X1).
1.2 Although primarily intended as a base for paint, chemical conversion coatings provide varying degrees of surface protection for magnesium parts exposed to indoor atmosphere either in storage or in service under mild exposure conditions. An example is the extensive use of the dichromate treatment (see 5.2) as a final coating for machined surfaces of die cast magnesium components in the computer industry.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D1732 Practices for Preparation of Magnesium Alloy Surfaces for Painting
SAE StandardAMS2475 Protective Treatments--Magnesium Alloys
Military SpecificationsDTD5562 (British), Clear Baking Resin for Surface Sealing Magnesium DTD911 (British), Protection of Magnesium-Rich Alloys Against Corrosion DTD935 (British), Surface Sealing of Magnesium Rich Alloys MIL-M-3171 Magnesium Alloy, Processes for Pretreatment and Prevention of Corrosion on
ICS Number Code 77.120.20 (Magnesium and magnesium alloys)