Influence of nanocrystalization on magnetoelastic Villari effect in Fe73.5Nb3Cu1Si13.5B9 alloy

The results of an investigation of the influence of thermal annealing on the magnetoelastic properties of Fe73.5Nb3Cu1Si13.5B9 soft magnetic alloy in both amorphous and nanocrystalline state are presented. A new method developed was used to apply uniform compressive stresses to the investigated ring core made of the alloy. The compressive stresses produced by external mechanical forces were applied perpendicularly to the direction of the magnetizing field. Due to the uniform distribution of stresses in the core brittle nanocrystalline alloys may be tested for stresses up to 10 MPa. The results revealed, that process of nanocrystallisation causes significant increase in the stress sensitivity of the Fe73.5Nb3Cu1Si13.5B9 alloy. Moreover the influence of stresses caused by external forces is more significant at relatively low values of the magnetizing field suggesting that these nanocrystalline soft magnetic materials are stress sensitive in the range of technical operation of inductive components based on such materials.