Speaking as an engineer.....
If you get the axle re-treated, the diameter will increase and the next time you install it will probably be very tight and most of the coating will be scraped off, thus starting the corrosion process again.
As for using a different material, you have to be very careful, generally manufactures choose materials based on
cost, weight, fatigue life, expected use so lets say you use titanium, strong, very light relative to section. The downside is you can get micro cracks when ground incorrectly (potential for sudden breakage) and very expensive (heat treatment processes) and will still corrode and will probably need to be replaced after a certain life time. Now if you use stainless steel, good corrosion resistance, but heavier, could pick up on forks (weld themselves together) so you can’t get it out again and more expensive (note some stainless will still corrode under the correct conditions.
Well thats my thoughts anyway.
Gannet
