TEM and nanoindentation studies on sputtered Ti 40Ni 60 thin films

Abstract

Ti 40Ni 60 thin films were sputter deposited from an equiatomic alloy target onto Si(1 0 0) substrates and the mechanical response of these films have been studied. The compositions of the films were determined by RBS. The transformation of the amorphous films into an ordered B2 Austenite phase on annealing was confirmed by electron microscopy. The effects of second phase segregation and superlattice formation and their implication on the electron diffraction patterns have been discussed. The mechanical response of the films to indentation was studied by a standard Hysitron triboindenter. The deformation behavior of the films was analysed via a series of load–displacement ( P– h) curves and the singular occurrence of intermittent discontinuities in the otherwise smooth P– h curves are attributed to the onset of plastic deformation. Mechanical response parameters like hardness and Young's modulus have been determined from the unloading curve as per the standard Oliver–Pharr analysis.