Most titanium things are alloys, probably with a higher melting point. Also, copper melts at a considerably lower temperature than Ti, but you'd have one hell of a time reducing copper to a puddle with a propane torch. Oxy/gas cutting torches don't work by melting the metal, they work by heating the metal and then burning it away (ok, oxidizing it away).

I'm still not sure if Ti is vulnerable to this kind of attack, and it's of minimal relevance to the question at hand.