MIL-DTL-5541F Salt Fog Testing
What is MIL-DTL-5541？
MIL-DTL-5541 is a military specification related to conversion coatings. This is produced by reacting with aluminum and its alloys as chemically transforming substances.
Military specification MIL-DTL-5541 (Chemical Conversion coating for Aluminum and aluminum alloys) is suitable for chemical conversion coating formed by the reaction of chemical conversion materials on aluminum and aluminum alloys. This specification has been approved for use by all departments and agencies of the United States Department of Defense, and although the standard was specifically prepared for dod applications, it is also used in many commercial applications.
A: For ingredients containing hexavalent chromium. The film is usually golden or brown in color, but in some cases can optionally be specified as colorless (colorless is described as "transparent").
B: For ingredients that do not contain hexavalent chromium. The film usually appears to have no color (no color is described as "transparent").
Corrosion protection class
Class 1A: For optimal corrosion resistance
Level 3: For corrosion protection where low resistance is required
Class 1A chemical conversion coatings are designed to improve the adhesion of paint coating systems on aluminum and aluminum alloys and provide corrosion suppression for unpainted items.
For example, this type of paint is used in tanks, pipes, and component structures where the inner surface does not need to be painted, but the outer surface does.
Class 3 chemical conversion coatings are designed to be corrosion resistant films for electrical and electronic applications where the contact resistance is lower than that of Class 8625A coatings and anodic coatings of the MIL-A-1 standard.
The coating thickness varies according to the immersion time. Because Class 3 coatings are thinner, they corrode more easily than Class 1A coatings. If the area around the electrical contacts needs to be painted, Class 3 coatings improve the adhesion of the paint system to aluminum and aluminum alloys.
JOEO offers testing services and test equipment for chemical conversion coatings on aluminium and aluminium alloys within the MIL-DTL-5541F standard range. Please contact our expert staff for military specifications: For more information on MIL-DTL-5541 and how our chemical conversion coatings can help you with your next project, contact us by phone or email to start your project now!
MIL-DTL-5541 is a military specification related to conversion coatings. This is produced by reacting with aluminum and its alloys as chemically transforming substances.
Military specification MIL-DTL-5541 (Chemical Conversion coating for Aluminum and aluminum alloys) is suitable for chemical conversion coating formed by the reaction of chemical conversion materials on aluminum and aluminum alloys. This specification has been approved for use by all departments and agencies of the United States Department of Defense, and although the standard was specifically prepared for dod applications, it is also used in many commercial applications.
Type
According to this test standard, there are the following types of chemically converted coatings:A: For ingredients containing hexavalent chromium. The film is usually golden or brown in color, but in some cases can optionally be specified as colorless (colorless is described as "transparent").
B: For ingredients that do not contain hexavalent chromium. The film usually appears to have no color (no color is described as "transparent").
Corrosion protection class
Class 1A: For optimal corrosion resistance
Level 3: For corrosion protection where low resistance is required
Class 1A chemical conversion coatings are designed to improve the adhesion of paint coating systems on aluminum and aluminum alloys and provide corrosion suppression for unpainted items.
For example, this type of paint is used in tanks, pipes, and component structures where the inner surface does not need to be painted, but the outer surface does.
Class 3 chemical conversion coatings are designed to be corrosion resistant films for electrical and electronic applications where the contact resistance is lower than that of Class 8625A coatings and anodic coatings of the MIL-A-1 standard.
The coating thickness varies according to the immersion time. Because Class 3 coatings are thinner, they corrode more easily than Class 1A coatings. If the area around the electrical contacts needs to be painted, Class 3 coatings improve the adhesion of the paint system to aluminum and aluminum alloys.
Test method
1.Corrosion resistance test.
Corrosion resistance tests require 5 test samples (3 inches wide, 10 inches long, and no more than 0.020 inches nominal thickness of aluminum alloy, The test sample shall be 2024-T3 aluminum alloy conforming to SAE-AMS4037 Class 1A conversion film, and 6061-T6 aluminum alloy conforming to SAE-AMS4037 class 3). After coating, the specimen should be dried at 60 to 100°F(16 to 38°C) for 24 hours. The specimen should then be subjected to a 5% salt spray test in accordance with ASTM-B117 for 168 hours, but important surfaces should be tilted 6±2 degrees from the vertical direction. After exposure, the sample should be washed under running water not higher than 100°F(38°C), blown with clean, dry, unheated air, and visually check whether it meets the requirements: a. According to the test specimen, there must be no 5 isolated spots or pits with diameters greater than 0.031 inches. Areas 0.25 inch from corners, identification marks and handling, or waiting points for salt spray exposure are excluded. Loss of colour shall not be grounds for rejection. b. In the combined surface area of all 5 test samples, no more than 15 isolated spots or craters, as tested by salt spray, cannot be greater than 0.031inch in diameter.
2 .Test the adhesive force of wet tape.
Prepare samples of aluminum alloy for test Method 1 Corrosion resistance test and samples of epoxy primer dry film (This film is a volatile organic compound (VOC) compliant epoxy polyimide primer according to MIL-PRF23377 or MIL-PRF-85582). In either case, the primer should be applied to a dry film with a thickness of 0.0006 to 0.0009 inches (0.6 to 0.9 mil) and dried according to the applicable primer specification prior to testing. , perform wet tape adhesion test. The test shall be performed in accordance with FED-STD-141 Method 6301.JOEO offers testing services and test equipment for chemical conversion coatings on aluminium and aluminium alloys within the MIL-DTL-5541F standard range. Please contact our expert staff for military specifications: For more information on MIL-DTL-5541 and how our chemical conversion coatings can help you with your next project, contact us by phone or email to start your project now!
