Here's an idea that's been knocking around my brain for a while. Why not use magnesium for tent stakes? In many cases such as soft ground, the absolute strength of the stake doesn't seem to matter as much; they just need to be strong enough to not bend. Any time I bent a stake has been from trying to overforce it, not wind or "in-use" demands. Magnesium and its alloys are much lighter than both aluminum (2/3 the weight) and titanium. And, in a pinch, you could shave a bit off the stakes as firestarter material.

Sourcing Mg rod to play with does seem a bit tricky, since industrial suppliers expect you to order in larger quantities than you need. Also, you do need to be mindful of accidentally igniting dust/shaving while machining.