MIL-DTL 5541 Contact Resistance Testing
‘Bringing New Ideas To The Surface’
MIL-DTL 5541 is a standard that specifies how to test the electrical conductivity and contact resistance of chemical conversion coatings on aluminium, aluminium alloys, and non-anodised substrates.
The military and aerospace industries use conversion coatings most widely, but many industries could benefit from using chemical conversion coatings on their components and parts.
PreTreat Ltd’s sister company, Walterisation Ltd, is currently one of only three in the UK that have the equipment to carry out this testing.
Electrical Conductivity Contact Resistance Testing
MIL-DTL 5541 Electrical Conductivity Contact Resistance Testing applies to conversion coatings on aluminium and aluminium alloys, as well as non-anodized substrates.
It covers two classes of conversion coatings:
Class 1A: offers optimal protection against corrosion for painted and unpainted surfaces.
Class 3: offers corrosion protection for materials requiring low contact resistance.
Class 3 coatings are thin, making them ideal for electrical applications. However, this also makes them less corrosion-resistant. As a result, Class 3 coatings must undergo salt spray testing and electrical contact resistance testing to ensure compliance with the standard.
MIL-DTL 5541 sets the contact resistance limit for Class 3 coatings at 5,000 microohms per in² with electrode pressure at 200 psi. After 168 hrs of salt spray testing, the resistance must be below 10,000 microohms per in².
Why Carry Out MIL-DIL 5541 Testing
MIL-DTL 5541 is important because it:
- Improves corrosion resistance
- Promotes paint adhesion
- Ensures electrical conductivity
- Minimises the risk of electrostatic discharge.
MIL-DTL-5541 is a critical specification within the aerospace industry, detailing the requirements for chemical conversion coatings applied to aluminium and aluminum alloys.
Many of our customers in this sector of industry send us both their salt spray testing and electrical contact resistance testing to be carried out all under one roof.
Walterisation deliver clear, accurate, and detailed results within a quick turnaround window. Alongside this, technicians are available for any questions regarding test results or data.