Yer gold is used, easy to work with. So is aluminium, easy to work with. You should see the machines in action as they fly along knitting the bondwires down
I only have experience doing manual wire bonding. It is extremely tedious and difficult. I only have about 12hrs experience on the machine though.
Interestingly enough, the bobbins we had (both alu and gold) had expiration dates. Since neither oxidizes indefinitely like copper or iron, I always thought it odd they had 'throw-away' dates on them. But extruding it right at the unit fixes that I guess. Any reason why they have to do it that way?