I believe the metal is zinc. I used to use this on dissimmilar metals (stainless and Aluminum) on boat hardware to reduce galvanic corrosion. There are better and way less messy chemicals available so I got away from that stuff. It might well be a viable thermal junction but I can guarantee that arctic alumina cleans up a lot easier!
Yeah, no doubt zinc, now that you mention it. And it's sure messy. I always carry lots of paper towels when I use it. But I think arctic silver would be just as messy if we weren't more careful and used larger quantities. Maybe when I get my Rolls Royce, I will use arctic silver on the wheel lugs and find out.