SITIS Archives - Topic Details
Program:  SBIR
Topic Num:  AF071-111 (AirForce)
Title:  Nonchrome Corrosion Protection for Conductive Coatings
Research & Technical Areas:  Materials/Processes

  Objective:  Identify the corrosion mechanisms of conductive coatings and develop a nonchrome-based corrosion inhibitive primer or additives.
  Description:  Conductive coatings are used on a variety of military aircraft to control electrostatic discharge and provide lightning strike protection. These coatings are typically based upon polyurethane or epoxy polymer chemistry. Conductivity is imparted through the use of a conductive pigment; silver, nickel, copper, and carbon pigments are commonly used. These coatings are applied over an aluminum or composite substrate in which a chrome-based primer is used to control corrosion. In an effort to reduce hazardous materials, the military and the aerospace industry are moving to incorporate nonchrome-based primers into modern aircraft. While nonchrome based primers have adequate corrosion protection over aluminum and composite materials, they do not inhibit corrosion of conductive coatings.

  PHASE I: The contractor shall identify a commercially available conductive coating as the baseline for evaluation. The contractor shall identify the corrosion mechanisms of this conductive coating when applied to aluminum and composite substrates and identify potential corrosion protection techniques.
  
  PHASE II: The contractor shall develop either a nonchrome-based primer for the baseline coating or develop corrosion as an additive to the baseline coating. The contractor shall characterize the corrosion, mechanical, physical, and electrical properties and behavior of the developed primer or additive. The contractor shall demonstrate manufacturing feasibility of the developed primer/additive.

  DUAL USE COMMERCIALIZATION: Military application: As mentioned, a variety of military aircraft utilize conductive coatings to control electrostatic discharge and provide protection for lightning strikes. Commercial application: Commercial aircraft could benefit from the use of nonchrome-based primers for the same applications.

  References:  1. Donatas Satas and Arthur A. Tracton; "Coatings Technology Handbook"; 2nd ed.,New York, NY, Marcel Dekker, 2001. 2. James H. Lindsay, "Coatings and Coating Processes for Metals", Materials Park, OH : ASM International, 1998.

Keywords:  conductive, coating, corrosion, nonchrome

Questions and Answers:
Q: 1. Can you provide a list of suppliers of qualified electrically conductive coatings to the Air Force?
2. Are aluminum panels with the non-chrome primer coated with the top coat commercially available? Or should the Phase I contractor apply the surface treatment, followed by the non-chrome primer and the topcoat?
3. What are the military specifications for the conductive coating?
A: 1. For this topic, we are expecting you to use a commercially available silver paint for example. It will at least allow you to reproduce the corrosion problem between silver and aluminum.

2. Yes, prepared panels are available. University of Dayton Research Institute (UDRI) services can be used for this purpose.

3. There is currenly no specification available for the conductive coating. As far as physical properties, you will want properties similar to MIL-PRF-85285.
Q: Can you tell what is the military specification of the non-chrome primer used for this application?
A: The non-chrome primer follows the MIL-PRF-23377. There is not a separate specification for non-chrome at this time. There are several non-chrome primers that are commercially available through Deft and PPG, for example.
Q: How to understand the statement from the Phase II objective: The contractor shall develop either a nonchrome-based primer for the baseline coating or develop corrosion as an additive to the baseline coating.
A: There is a typo. It should read "or develop corrosion inhibitors as an additive to the baseline coating."
Q: 1. Can you provide a list of suppliers of qualified electrically conductive coatings to the Air Force?
2. Are aluminum panels with the non-chrome primer coated with the top coat commercially available? Or should the Phase I contractor apply the surface treatment, followed by the non-chrome primer and the topcoat?
3. What are the military specifications for the conductive coating?
A: 1. For this topic, we are expecting you to use a commercially available silver paint for example. It will at least allow you to reproduce the corrosion problem between silver and aluminum.

2. Yes, prepared panels are available. University of Dayton Research Institute (UDRI) services can be used for this purpose.

3. There is currenly no specification available for the conductive coating. As far as physical properties, you will want properties similar to MIL-PRF-85285.
Q: Can you tell what is the military specification of the non-chrome primer used for this application?
A: The non-chrome primer follows the MIL-PRF-23377. There is not a separate specification for non-chrome at this time. There are several non-chrome primers that are commercially available through Deft and PPG, for example.
Q: How to understand the statement from the Phase II objective: The contractor shall develop either a nonchrome-based primer for the baseline coating or develop corrosion as an additive to the baseline coating.
A: There is a typo. It should read "or develop corrosion inhibitors as an additive to the baseline coating."

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