Al won't help. Its reluctance is about the same as air IIRC. So its not really useful. As for Iron, I disagree. It would become magnetised itself, but it would also draw much many more flux lines into it from the surounding air. At least thats how I understand it from working on a coilgun.
I asked an engineer (designs PC power supplies for a living) about this, he recommended permalloy from the McMaster catalog.
|