Pat Flannery wrote:

Okay, I'm in 166 pages so far... and _this_ is interesting.
The fact that the titanium would actually _burn_ and not just melt was
very unexpected.

Titanium is in fact one of the more reactive metals. It can be used as a structural metal (unlike e.g. sodium) because
any cut face reacts quickly with atmospheric oxygen. The oxide layer is tightly bound to the metal underneath. This
prevents oxygen from further attacking the metal. Same thing happens with aluminium. It also happens with iron, but in
that case the oxide doesn't bond very strongly with the metal, allowing oxygen to further corrode it.