Nb-Ti-Ni alloy is one of the candidates for hydrogen permeation membranes. The hydrogen permeability of a membrane depends on its thickness, and mechanical properties such as the fracture toughness of the membrane are important to ensure reliability and durability. In the present work, micro-mechanical tests have been carried out for melt-spun Nb-Ti-Ni thin films consisting of amorphous and nano-crystalline phases. The relationship between the mechanical properties of the melt-spun films and the microstructural changes occurring in the films due to heat treatment has been also discussed. The Nb-Ti-Ni alloy thin films were prepared by the melt-spun technique and then heat-treated at 873-1173 K. Micro-sized cantilever specimens with dimensions of 10 × 10 × 50 μm3 were prepared by focused ion beam (FIB) machining. Fracture tests were carried out using a mechanical testing machine for the micro-sized specimens; the testing machine was developed by us. In addition, microstructures were observed by transmission electron microscopy (TEM). The fracture toughness (KQ) value decreased up to 823 K, and it increased above 1173 K. The specimen heat-treated above 1173 K showed ductile fracture. The fracture morphology of the specimen heat-treated up to 1023 K showed grain boundary fracture characteristics, and that of the specimen heat-treated at 1173 K changed to transgranular fracture.

Polycrystalline Galfenol (Fe-Ga-X, X=Al, C, Zr etc.) alloys were fabricated as a bulk sample from ark-melted and annealing process method for enhancing various engineering applicability. (Fe-Ga0.15-Al0.05)99.0-Zr0.5-C0.5 [at.%] sample showed a maximum magnetostriction of 134 ppm as well as a tensile stress over σ=800MPa. This large magnetostriction is caused by A2 phases without the excessive precipitation of ordered phases such as fcc ordered L12 and bcc ordered D03 phases. Secondarily, we will introduce an application as a smart torque sensor by utilizing Galfenol-ring around the steering shaft for steering-by-wire system of automobile. In this system, a torque sensing system by using the magnetostrictive ring of FeGa (Galfenol) alloy was developed and magnetic flux leaked from the Galfenol ring attached on the rotating shaft was experimentally measured by using two differential Hall probe sensor. As a result, the sensitivity in (Fe0.80Ga0.15Al0.05)99Zr0.5C0.5 ring increased by 2.9 times in comparison with the (Fe0.80Ga0.15Al0.05)98.5C1.5 alloy at rotations speed 500 rpm.