Effects of mechanical activation on self-propagating high- temperature synthesis (SHS) of porous Nitinol ,

This present work introduces the research on the effects of mechanical active time on Self-propagating High-temperature Synthesis (SHS) of porous Nitinol (NiTi). The experimental results showed that the pre-heating temperature which was necessary for the occurrence of SHS reaction strongly decreased with the increasing of mechanical active time (in the range of 0 to 2.0 hours). With the absence of mechanical activation or the mechanical active time less than 1.0 hour, no reaction occurred although the pre-heating temperature and ignited temperature were relative high (Tp = 6000C and T = 20000C). However, when the mechanical active time increased in the range of 1.5 to 2.0 hours, the reaction between Ni and Ti occurred. Depending on the pre-heating temperature, the reaction occurred at simultaneous mode (Tp ≥ 550 C) or self-sustained mode (Tp < 500 C).