Peculiar features of electrical resistivity and phase structure in 3-D porous nitinol after selective laser sintering/melting process

Abstract

The main goal of this study is the peculiarities of shape memory effect in a porous nickel–titanium (NiTi intermetallic phase referred to as nitinol) fabricated via the selective laser sintering/melting process. The phase and structural transformation behaviour of the intermetallide is characterized by means of the scanning electron microscopy, energy dispersive X-ray and X-ray analysis. The effect of the laser sintering parameters and additional heating on the phase content and the thermal dependence of the electrical resistivity are discussed. Peaks and bulbs of the electrical resistivity are found to correspond to the start and finish temperatures of the austenite-to-martensite and reverse phase transitions, and this discovery can be useful for the shape memory effect estimation and optimization. Advantages and shortcomings in the application of this porous material as biological microelectromechanical systems are briefly considered.