Structural and phase transformations in Ni₃Fe during high-dose ion implantation

The results are given for experimental studies of the structural-phase state formed in the surface and near-surface layers of a disordered polycrystalline Ni₃Fe alloy during high-dose ion implantation. The studies used Auger electron spectroscopy, transmission electron microscopy, x-ray structural analysis, and microhardness measurements. The ion implantation was done using the "Raduga" vacuum arc source with a multicomponent cathode of composition Zr (89.5 wt. %) + C + N + O with an acceleration voltage of 50kV. The implanted ion dose was varied in the range (6.0·10¹⁶-6.0·10¹⁷) ions/cm². It was established that in the surface layer which is alloyed during ion implantation there is amorphization with simultaneous formation of finely dispersed ZrO₂ particles whose dimensions increase with increasing implanted ion dose; this is accompanied by an increased internal mechanical stress. Beyond the ion-implanted layer a sublayer about 10 μm thick with a high dislocation density is formed (the "long-range action" effect). The results of microhardness measurements correlate with the data from structural studies.