Structure of the near-surface layer of NiTi on the meso- and 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 5-50 [mu]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

Structure and Multistage Martensite Transformation in Nanocrystalline Ti-50.9Ni Alloy

An electron microscopic study of the evolution of the size, morphology, and spatial distribution of coherent Ti3Ni4 particles with a change in the aging temperature in a nanocrystalline (NC) Ti-50.9 at % Ni alloy with an inhomogeneous grain–subgrain B2-austenitic nanostructure has been carried out. It was found that with an increase in the aging temperature, along with a change in the size and shape of Ti3Ni4 nanoparticles, their spatial distribution changes from location at dislocations to precipitates at subboundaries. Research has shown that the presence of different types of internal interfaces in the nanostructure contributes to the heterogeneous distribution of coherent Ti3Ni4 nanoparticles in the volume of the B2 matrix, which is associated with the precipitation of particles in the region of low-angle subboundaries and the suppression of the Ti3Ni4 precipitation in nanograins with high-angle boundaries. The difference in the structural-phase state of nanograins and subgrains regions is the main reason for the implementation of the anomalous R-phase transformation effect in the sequence of multistage martensitic transformations B2↔R↔B19′

Dislocation structure in coarse-grain copper after ion implantation

Translated from Russian (Fiz. Khim. Obrab. Mater. 1996 (4) p. 14-20)SIGLEAvailable from British Library Document Supply Centre-DSC:9023.190(VR-Trans--9156)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo