The addition of dysprosium made it easier to induce magnetostrictive responses by making the alloy require a lower level of magnetic fields.
Magnetic heat treatment is shown to improve the magnetostrictive properties of Terfenol-D at low compressive stress for certain ratios of Tb and Dy.
[4] Due to its material properties, Terfenol-D is excellent for use in the manufacturing of low frequency, high powered underwater acoustics.
[6] Similarly, magnetostrictive actuators have also been considered for use in fuel injectors for diesel engines because of the high stresses that can be produced.
Finally, its mechanical expansion tends to be proportional to the imposed magnetic field, making injector needle position continuously controllable.
An injector needle directly operated by Terfenol-D can have lifetime durability on an engine cylinder head while enabling unprecedented control over each injection event throughout its entire duration.
There are four methods that are used to produce Terfenol-D, which are free stand zone melting, modified Bridgman, sintered powder compact, and polymer matrix composites.
The first two methods, free stand zone melting (FSZM) and modified Bridgman (MB), are capable of producing Terfenol-D that has high magnetostrictive properties and energy densities.
The MB process offers a minimum of 10 mm diameter size and is only restricted due to the wall interfering with the crystal growth.
[9] The resulting microstructures of these powder based methods differ from the solid crystal ones because they do not have a lamellar structure and have a lower density.