I think the hole would expand because the alloy will expand outwards as a whole unit, kind of like heating a roller bearing up so it can be slipped onto an electric motor drive shaft! we used inductive coils to induce an electromagnetic field into the bearing and it would warm up to about 130 degrees and expand about 40thou... thats the difference between slipping on, or destroying the bearing and shaft by beating it with a hammer trying to make it fit!