How bout titanium? That'll be a stress reliever for you for sure. I hear you have to really know what you're doing - or maybe it's just welding.
Depends on the alloy, but Titanium is no joke to machine. It "work hardens" locally, so if get the cutter to dwell to long (feed) some alloys get rock hard at the effected area.
10+ years ago, I made axles and steering stems from the stuff almost weekly, I figured it out, but it still sucked. High rates of feed and low RPM's (sounds backwards, but it worked).
6Al 4V (6% Aluminum, 4% Vanadium) was the stuff I used. Anyway, sometimes you are better off making that stuff from heat-treatable steel alloys and maximizing your inherent strength/durability with the better steels and just engineering everything "thinner".
Titanium is indeed a miracle alloy, but your weight savings (all things being equal) is 40% at best over steel, that is a lot, but you also have to make some design/application considerations, so sometimes your weight savings only gets in the 25% after all is said and done on some components. But, as Shelby Smith said, if he had the dough, EVERYTHING would be titanium!
