Aluminium forms its own layer, you can force it to get thicker and end up with essentially a form of sapphire on the surface.
When we used to shot peen items for fatigue testing, it increased the fatigue resistance by having the peened areas become super ductile, thereby bending instead of fracturing microscopically where the crystals align, kinda like having a bundle of long pieces of spaghetti vs. a bundle of short pieces, which is more flexible. Only problem I can see is that it'll leave the corner vulnerable and when it eventually rounds out, it'll just tear the whole region out.
Phantom, why don't you make a chainring by sandwiching layers of aluminium and solid carbide with an outer ring of solid carbide. Then PMP etch enough holes in it to make it lighter. Then sit back and realize for the same price, you can buy tons of chainrings. Or cassettes.