TEM studies of the nitrided Ni-Ti surface layer.

The structure of surface layer, obtained on the nearly equiatomic Ni-Ti alloy after nitriding under glow discharge conditions at temperatures 700 or 800 degrees C, was investigated. The structural characterization of the intruded layer was performed on cross-sectional thin foils by the use of the transmission and scanning electron microscopes. The obtained results show that the nitrided layers consist mainly of the nanocrystalline TiN phase and small amount of Ti(2)N. Between the nitrided layers and beta-NiTi matrix an intermediate Ti(2)Ni phase layer was observed.