1. Home
  2. ⚙ Model Engineering in the UK
  3. Aluminium Surface Treatments

Aluminium Surface Treatments

The current project on the drawing board is a small supercharger . Essentially it's a vane compressor with tufnol vanes that run against an cast aluminium casing. I need some wear resistance on the aluminium bore surface that is better than the cast ali. I could fit a cast iron liner but I'm concerned about differential expansion and the thermal barrier that the joint may make. I'd like to know what surface treatments can be applied to cast aluminium to give a wear resistant coating. There must be some plating or anodising that will do the trick. I'm sure that it's been used in motorcycle cylinder bores.

Thanks

Charles

Reply to
Charles Ping
Loading thread data ...

How about hard anodising?

Regards, Tony

Reply to
Tony Jeffree

Thanks Tony - good idea.

However having had a look at

formatting link
I am concerned that being selective (ie: anodizing only the bore and nothing else) may be expensive - the website quotes "Masking is labour intensive and can be very expensive." That's frightening when the sales blurb says it!

I suppose I could machine it fully first and anodise the whole thing

- a VPN of 400-460 isn't unworkable - it's still bloody hard though!

Charles

Reply to
Charles Ping

Charles I have a distant memory that anodising increases the size of the material. If this is true, in your case it might reduce the bore size. Check before final machining

Regards GrimReaper

Reply to
GrimReaper

As a first aproach, I wouldn't care about wear. Aluminium isn't so bad. If you do make the castings by your own, use "pistonium". Pistons are generaly cast with an overeutectic alloy with Si. Silicon is very wear resistant and the crystals embedded in the Al protrude a bit if the Al wears. Next better solution would be hard anodising it. If you are still not satisfied, you can crome plate it. The method used in IC engines is a complicated process of nickel (+ crome?) plating. It has a porous surface and so needs oil to get the most out of it.

I personaly would use pistonium or chrome plate the cylinder.

HTH, Nick

Reply to
Nick Mueller

What material are you using for the rotor ?

Rotor / vane wear was a problem with the sliding vane air pumps I used.

-- Jonathan

Barnes's theorem; for every foolproof device there is a fool greater than the proof.

To reply remove AT

Reply to
Jonathan Barnes

Aluminium slotted rotor. Tufnol blades.

Charles

Reply to
Charles Ping

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.