Felix's sword is often referred to by name as Karaghul, Gotrek's axe is only ever referred to as Gotrek's axe.
Does it have a name?
I know where he got it:
He gained this weapon during his excursion into the northern Chaos Wastes, where he recovered it from the body of the dead son of King Thangrim Firebeard.
But not its name, if it has one.
The Chaos champion Arek Demonclaw has a vision in which:
We see an ancient dwarf runesmith forging the axe for Grimnir.
So it's clearly very important.
If it does have a name and it's somehow a spoiler, please wrap it up in a spoiler tag!
Here's himself with the axe. (in his right hand)