NiTi shape memory alloy: Physical and tribological characterization

Abstract

The current research work focuses on the mechanical and tribological behavior of an NiTi shape memory alloy (SMA) processed with the help of powder metallurgy. SMAs have found applications in the medical, space and aerospace industries with usage in the manufacturing of microelectromechanicals (MEMS) and as actuators in the electronic industry. The wear behavior of a material greatly affects its performance. The wear behavior of an SMA can be determined with the help of the dry abrasion test. The increase in binder content and rotational speed at a constant load increases the wear rate of SMA alloys. The coefficient of friction decreases with the usage of alloys. A decrease in density has been found, as well as porosity, with the increasing content of binder in the alloy. Density decreases from 6.7 to 5.1 g/cm3 while porosity decreases from 57 to 23% with increased binder content. Scanning electron microscopy (SEM) and X-ray diffraction has been used for the investigation of surface morphology and phases present in the alloy.