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 °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 Ti₂N. Between the nitrided layers and β‐NiTi matrix an intermediate Ti₂Ni phase layer was observed.