Structure of the Near-Surface Layer of NiTi on the Mesoand Microscale Levels after Ion-Beam Surface Treatment.

Using the EBSD' SEM and TEM methods' the structure of surface layer of polycrystalline NiTi alloy samples was examined after the modification of material surface by the pulsed action of mean-energy silicon ion beam. It was found that the ion beam treatment would cause grain fragmentation of the near-surface layer to a depth 550 |¿m; a higher extent of fragmentation was observed in grains whose close-packed planes were oriented approximately in the same direction as the ion beam was. The effect of high-intensity ion beam treatment on the anisotropic behavior of polycrystalline NiTi alloy and the mechanisms involved were also examined. [ABSTRACT FROM AUTHOR]