Experimental investigation of Terfenol-D's elastic modulus

The variability of Young's modulus (the Delta E effect) in giant magnetostrictive Terfenol-D has a significant impact on the performance and modeling of Terfenol-D transducers. In this investigation, Terfenol-D's modulus of elasticity is characterized under controlled thermal, magnetic, and mechanical loading conditions. Quasistatic cyclic compressive stress testing methods are used to quantify the variability in Young's modulus over a wide range of DC applied magnetic fields and stresses. Apparent elastic modulus changes of four-fold or more are demonstrated through the variation of a DC applied magnetic field. The effect of decreasing cyclic stress amplitude giving rise to an increase in Terfenol-D's apparent elastic modulus is also examined.