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Ti being such a poor thermal conductor is what makes it such a bastard to work. Machining it takes copious amounts of cooling fluid, and if you’re not generous enough it goes badly wrong. Mike Burrows has a souvenir piece of titanium that he was turning into a BB axle; he was boring it out and the drill bit spot-welded itself inside the piece and the drill shank shattered. He mounted on a piece of wood as a reminder.
Also high thermal conductivity works against copper, as the energy generated at the fracture surface rapidly dissipates through the body of the fragment, lowering the surface temperature so that combustion never gets a chance. By comparison, for example, Ti is a poor thermal conductor and is more reactive and harder than copper, so it has almost ideal characteristics for creating very bright white grinding sparks.