Corrosion behavior on orthopedic NiTi alloy with nanocrystalline/amorphous surface

▶ Nanocrystalline layer with partial amorphous structure is formed on the surface of NiTi alloy. ▶ The surface harness is notably improved. ▶ The corrosion resistance is improved due to the presence of nanocrystallines with partial amorphous structure. ▶ Passive oxide layer can be easily formed due to nanocrystallines in the early corrosion process. ▶ The passive oxide layer will be degraded after long exposure.