Advanced Powder Technology, Vol.29, No.10, 2456-2462, 2018
Densification and microstructural evolution of spark plasma sintered NiTi shape memory alloy
The effect of particle size and sintering temperature on the densification and microstructural characteristics of nickel-titanium shape memory alloy (NiTi-SMA) has been investigated using spark plasma sintering (SPS) process. The Ni and Ti elements in different particle sizes were alloyed in the composition of Ni50.6Ti49.4. The milled NiTi powders were consolidated using SPS process in a temperature range of 700-900 degrees C. The densification was characterized by plotting temperature, current and relative displacement of punch as a function of holding time. The results showed that a maximum relative density of similar to 98% can be achieved for NiTi-SMA with an average particle size of 10 mu m at a sintering temperature of 900 degrees C. The microstructure of the sintered NiTi-SMA was examined using scanning electron microscope (SEM) and composition of NiTi alloy was analyzed using energy dispersive spectroscopy (EDS) analysis. The effect of sintering temperature on the microstructural evolution and transformation was also studied. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.