NAVAIR Hexavalent Chromium Minimization Status
Abstract
NAVAIR has set forth a comprehensive goal for the development and qualification of nonchromated materials. Candidate alternative materials have often been developed and evaluated to the bare minimum of performance requirements, leading to reduced corrosion protection and loss of robustness in the materials protection scheme. The NAVAIR nonchromated materials goal is to: Identify, test, validate and implement non-chromate, Class N primers and surface preparations which are as broad in capabilities and performance as current chromated, Class C, primers and surface preparations. To this end, demonstrated capabilities must include performance across multiple alloys/substrates, with and without subsequent topcoats and specialty coatings. Alternative materials must perform a variety of uses, such as protection of faying surfaces, galvanic corrosion protection in dissimilar materials interfaces, wet installation of fasteners and bushings, resistance to SCC, embrittlement and exfoliation damage and other traditional uses of chromate primers, metal finishes, and sealants. Coatings must perform over Type I and Type II conversion coatings per MIL-DTL-81706/MIL-DTL-5541. Additional surface conditions/finishes that the coating must demonstrate compatibility and full performance over are finishes such as: Type I, IC, II, or IIB anodized aluminum per MIL-A-8625, sacrificial coatings (such as IVD-Al, Cd, Zn-Ni, etc.), touch-up on Fe alloys, other conversion coated or anodized light metals such as Ti, Mg, and Zn, and composite substrates. Full implementation will also require demonstration of equivalent performance in adhesion filiform, humidity, and fluid resistance properties for all the materials and applications currently protected by Class C coatings and finishes. This talk will address the current and planned alternative materials efforts, status of approval and technology implementations, and identify gaps and shortfalls in the current technologies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2010
- Accession Number
- ADA553976
Entities
People
- Bill C. Nickerson
Organizations
- Naval Air Systems Command