Investigation on Mechanical Properties of Deformation TiNi Thin Films

The TiNi thin films were deposited onto copper substrates by magnetron sputtering. Tensile tests were carried out on CSS-44100 electron universal test-machine. X-ray diffraction profile Fourier analysis method and the Nano-Hardness Tester have been used to study the mechanical properties of deformation TiNi thin films. The mechanical properties of metals and alloys should be determined primarily by dislocation structure among these objects. The results showed that the dislocation density and the deformation storage energy density increased with the increasing elongation. Microhardness was calculated from the dislocation data. The results showed that the microhardness values were not having good agreement when comparing the calculated values with the measured values. The oxide layer on the surface and the precipitated phases of TiNi thin film affect the measured values of microhardness. The microhardness measured values were larger than the calculated values. The surface micrographs of the TiNi thin film were obtained using scanning electron microscopy (SEM). The experimental results showed that a series of parallel cracks grew in a concerted fashion across the thin film, and the cracks were equally spaced.