MAGNETIC-PROPERTIES OF NANOCRYSTALLINE MECHANICALLY ALLOYED FE-M (M =AL, SI, CU)

Fe100-xMx powder blends with M = Al, Si and Cu and x less-than-or-equa l-to 50 were mechanically alloyed. In all three alloy systems, disorde red bcc solid solutions were formed which are unstable in the immiscib le Fe-Cu system. A nanocrystalline state with average grain sizes of 1 5-30 nm and high internal strain was established. The saturation magne tization of mechanically alloyed Fe-Al and Fe-Si is very similar to th at of the corresponding as-cast alloys. For the unstable Fe-Cu alloys, it behaves like a simple magnetic solution up to a Cu content of 30 a t. %. Generally, relatively high coercivities of up to 40 A/cm occur i ndicating a predominant influence of internal stresses on the soft mag netic behavior via magnetostriction. The lowest coercivity of 3 A/cm w as measured for Fe90Cu10.