A chrome-free conversion coating and sealant for aluminum and its alloys
For over fifty years, chromates have been the standard against which other conversion coatings and/or sealants have been judged. Due to current environmental and safety concerns, they are being removed from use. This paper presents neutral salt-spray, filiform primer adhesion and electrical conductivity data on a commercial chromate-free, inorganic and non-toxic conversion coating used with a new and unique sealing emulsion. The seal is an organic water based emulsion which when dried on a permanganate based conversion coated aluminum surface will be polymerized, or cured, when heated to 250--300 F for 20 seconds or longer. The higher the temperature, or period of time, the greater the degree of polymerization. The polymerized film is as electrically conductive as chromate films and easily accepts and bonds to applied primers. For in-service repair a conventional heat-gun maybe used. For large surfaces, any other conventional heat source may be used. The 6061-T6, 7075-T6, and 2024-T3 series wrought alloys were tested and directly compared to current chromate based conversion coatings. The tests showed equivalent or superior results in all cases.
- Research Organization:
- Sanchem, Chicago, IL (US)
- OSTI ID:
- 20002540
- Report Number(s):
- CONF-990401-; TRN: IM200002%%540
- Resource Relation:
- Conference: Corrosion NACExpo 99, 54th Annual Conference and Exposition, San Antonio, TX (US), 04/25/1999--04/30/1999; Other Information: 1 CD-ROM. Operating Systems: Windows 3.1, '95, '98 and NT; Macintosh; and UNIX; PBD: 1999; Related Information: In: Corrosion 99: Proceedings, [3500] pages.
- Country of Publication:
- United States
- Language:
- English
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