Aluminum vs. Titanium

I was wondering what the difference was between Aluminum and Titanium. The way I always thought you could tell was Aluminum always sounds dead when you hit or drop it. Where as Titanium seems to ring real loud and is way harder to cut. Is this correct? And if anyone has ever scrapped titanium is there a price difference?

When I took a titanium muffler in from a motorcycle, in July 2015, the yard guy put it to a grinder and told me it sparks a certain way. It paid $.55 per pound at a time when aluminum was about $.37 per pound here.

When you grind Ti it will spark a bright white, Ti is lighter than alum. most of the time. Right now Ti is about the same price as Alum. or less. Way back when I remember Ti was $5.00 to $6.00 a lb.

Thank you. I guess I must just be finding a different mix of aluminum then.