The Dynamic Magnetostrictive Properties of Alfenol

The magnetostrictive properties of Alfenol, a cold‐rolled Fe‐Al alloy, for use as the active element in electromechanical transducers were compared with those of nickel. The aluminum content of the Alfenol was varied from ten to sixteen percent. After a suitable heat treatment a maximum effective electromechanical coupling coefficient of 0.31 was obtained with 12‐Alfenol biased to four oersteds. The maximum effective coupling coefficient of 13‐Alfenol was observed to be approximately the same as that of nickel, 0.27. While the effective coupling coefficient of 13‐Alfenol is smaller than that of 12‐Alfenol, the product of the characteristic frequency times the thickness squared for 13‐Alfenol biased to twelve oersteds was twice that of 12‐Alfenol biased to four oersteds and four times that of nickel biased to thirteen oersteds. Performance is given for similarly constructed Alfenol and nickel transducers.