Problems with aluminium-silicon coating

[gasper]

Hello,

I have one qustion about the sheets which are coated with 90% of Al and 10% Si.

When and why start the flaking of aluminium-silicon coat? What is the reason for this problem?

Best Regards,

Gasper

[Gordon]

Hi Gasper

to the Surface Engineering Forum.

We will need much more detailed information to enable us to answer your questions properly.

• Substrate material, size, surface preparation etc.
• Coating process details
• Coating thickness
• Service application and environment
• Details of coating failure
  

The only thing I will say is that with any coating process; substrate preparation is the key, get this important stage wrong and even the best coating is likely to fail.

[gasper]

Hi Gordon,

If is possible I would like to know about this problem more generally. On what I have to be careful? How to storage this kind of material? When could occur flaking of coating,...etc?

Best Regards,

Gasper

[Gordon]

Hi Gasper

We really do need more information. It is difficult to give an answer without knowing how the coating is applied, it's thickness and intended use etc..

[gasper]

Hi Gordon,

It was use dip-coating process, material was DX53D + AS and the thickness AS120. The material is use for exhaustsystems.

I hope that this will help you.

Best Regards,

Gasper

[Gordon]

Hi Gasper

This link is to a product brochure, but it should provide some basic information:
http://www.corusautomotive.com/file_sour...chure.pdf

The main issue with storage is to ensure product is kept dry. Moisture trapped say in tightly wrapped coils of aluminised sheet may suffer serious corrosion, which ordinarily would not be a problem to exposed surfaces.

Welding operations on aluminised steel will destroy the coating local to the weld. Post welding protective treatments/coatings will be needed around the welds.

Hope that helps.

[gasper]

Hi Gordon,

It will help a lot.

Thank you.

Best Regards,

Gasper