Just from the pictures and the description, I honestly don't think so. Both materials would expand about the same and because of the mode of failure it might lock it together worse.
Personally I would try: liquid nitrogen on the broken stub to see if I could get it to shatter, drill/tap reverse threads into it and use an impact to try and shock it loose the opposite direction, use a drill press/mill and just start hogging that stub out of it.
The thing is, there's no guarantee that the splines aren't hurt in the case as well, which I bet they are.