A combination of sputter coating and ion bean implantation will be used to produce beta phase intermetallic compounds on the surface of base metals. The superelastic properties of the beta phase are expected to severely limit the nucleation and propagation of low cycle fatigue cracks. In the first phase of the study, NiTi superelastic microalloys will be prepared by sputtering thin films onto Cu and Ni substrates. Their composition, transformation temperature and crystallography will be determined. In the second phase of the study adherent films of superelastic material will be produced on base metal specimens by ion beam mixing. The effects on low cycle fatigue properties will be studied.
