| Title |
Thermal decomposition behavior of nanocrystalline NiTi |
| Authors |
최근섭(Keun Seob Choi) ; 김도향(Do Hyang Kim) ; 홍경태(Kyung Tae Hong) |
| Abstract |
Formation and thermal decomposition behavior of nanocrystalline structure in NiTi intermetallics have been investigated by a combination of X-ray diffraction analysis, scanning/transmission electron microscopy, differential scanning calorimetry. Mechanically alloyed Ni_(50)Ti_(50) consist of 5-15 ㎚ size grains with a disordered b.c.c. structure and decomposes by eutectoid reaction into Ni₃Ti and NiTi₂ forming an endothermic peak at the temperature range of 450℃-550℃ Such a low-temperature eutectoid reaction is attributable to the ㎚-scale structure with a large amount of defects accumulated during mechanical alloying process. The occurrence of these transformation is closely related to the unique features of the microstructure in the mechanically alloyed powders. |