Coating options for Aluminium?

[Th232]

This was prompted by Modamag's Exotic Coating Services thread and the ceramic coated Surefire feeler thread that Modamag and ElectronGuru have.

Short version: What kinds of coating options are out there for Al?

Long version:
I've been looking through various coatings for Al, and I seem to have found three main types: anodising, coating with another metal, coating with ceramics.

I've got a fair handle on anodising and coating with other metals, so far I've seen coating with nickel, chrome and gold, not to mention anodising of various types.

From what I've read, TiN and its variants can adhere to Al, but McGizmo has said here that they tend not to hold up as well as anodising when done on Al.

I've also been reading up on other ceramic coatings and getting a grasp on those, but any experience with how those have held up would be greatly appreciated. Do they have the same issue as with TiN?

Other than that, are there any options I've completely missed?

In case anyone is wondering, this is for a headlamp project for myself and a couple of mates, so pointers to places that do small runs would also be great.

Thanks!

 

[KuKu427]

TiN bond/adheres pretty well to smooth Al and will stand up to keys and coins.

http://www.youtube.com/watch?v=vo9bQ8JXCpQ
http://www.youtube.com/watch?v=Ko2aS6GaV2c
http://www.youtube.com/watch?v=EbZ3a2QY5QM
http://www.youtube.com/watch?v=z5v8rmsKEWk
http://www.youtube.com/watch?v=gt9WusSGj9g

However, the tube shown above was one of 5 tubes sent in to be coated and the only one to have TiN homogeneously coated over the entire area of the tube. I'm not exactly sure why but the fact that I left the original HAIII anodizing on could be a factor. :oops: Also, TiN seemed to have a real problem with adhering to knurling.

Further more, after EDCing the TiN light for about a month, even the good tube showed signs of flaking on the knurling.

If you want to give TiN a shot. I would suggest picking a smooth light.

 

[will]

I had 2 Mini-Mags ceramic coated a few years back.

The results can be found from the 85th post down in this thread


http://www.candlepowerforums.com/vb/showthread.php?t=114722&referrerid=4688

I am not sure what Modamag is offering for a ceramic coating, so this might not be the same type of coating.

 

[65535]

I think dark gray TiCN coatings are the way to go, unfortunately aluminum melts at the temps required to coat the substrate.

 

[Th232]

Thanks for the info guys, seems like this'll be a more complex issue than I expected if I want to go past HAIII.

Will, interesting results with the ceramics. Sounds like the stuff we use to hold samples in our furnace, very good insulator that stuff!

Has anyone tried Cerakote or similar on a flashlight? I've found some info saying that it can bond to Al if the surface is sufficiently roughened, but beyond that it gets a bit murky.