Microscopic superelastic behavior of a nickel-titanium alloy under complex loading conditions

The microscopic superelastic behavior of a nickel-titanium (NiTi) alloy has been studied by instrumented indentation experiments using both spherical and pyramidal (e.g., Berkovich) diamond indenters. The indentation load–displacement curves for a superelastic NiTi and an annealed copper were obtained under a range of indentation conditions. We show that indentation-induced superelasticity exists under both spherical and pyramidal indenters, which may be exploited for many applications, ranging from microelectromechanical systems to surface engineering.