Influence of aging on damping behavior of TiNi/TiNi alloys synthesized by explosive welding

The influence of aging time, measuring frequency and strain amplitude on the internal friction of TiNi51/TiNi50.2 sandwich composite was investigated. The DSC and internal friction measurements were employed to characterize the sample. The two internal friction peaks of the specimen were confirmed corresponding to the reverse transformation of TiNi51 and TiNi50.2 component, respectively. The internal friction as a function of the temperature at different measuring frequencies was presented and it was found that the height of both internal friction peaks increased with decreasing frequency; however, the increase corresponding to TiNi50.2 component was larger than that of TiNi51 component. Furthermore, the internal friction of the TiNi/TiNi composite alloy decreased with increasing the measuring strain amplitude. The height of internal friction peak of TiNi51 component increased with increasing the aging time, whereas that of the TiNi50.2 component did not change significantly. The increase in internal friction of TiNi51 appeared to be associated with the formation and growth of precipitate during the aging process.