Fatigue tests of Ni-P amorphous alloy microcantilever beams

Development of micromachines and MEMS (microelectromechanical system) devices are making steady progress at present. The size of components used in these micromachines and MEMS devices is expected to be of the order of μm, and the mechanical properties of such materials may be different from those of bulk materials. Therefore, the evaluation of mechanical properties such as Young´s modulus, tensile strength and fatigue properties is essential for the design of micromachines and MEMS devices. Young´s modulus, fracture stress and hardness of thin films and small elements of silicon single crystals have been measured. In addition to modulus and strength of such micro-sized materials, the fatigue properties are extremely important to design micromachines and MEMS devices. However, there have been few fatigue data for micro-sized materials, and the fatigue properties of such materials are still unclear. In the present study, fatigue life and fatigue crack propagation tests have been performed on Ni-P amorphous alloy microcantilever beams by using a newly developed fatigue testing machine.