Microstructure and phase composition of a zirconium coating-silicon substrate system treated using high-current electron beams

The results of structural-phase conversions in a zirconium coating-silicon substrate system treated with low-energy high-current electron beams (LHEBs) are presented. It is revealed that the action of LHEBs with energy densities of 8–10 J/cm 2 leads to the formation of a eutectic layer containing clusters with a characteristic size of 40–50 nm (the melt of ZrSi 2 and silicon) at the zirconium-silicon interface. After the energy density reaches 12 J/cm 2 , silicon dendrites and regions of silicide crystallites are formed in the surface layer 20–30 μm thick. Data on the characteristic sizes of dendrites and eutectic clusters have made it possible to perform numerical estimation of the surface-melt overcooling (12–25 K), the temperature gradients (3.7 × 10 7 −1.6 × 10 8 K/m), and the interphase boundary velocity (0.8−3.2 × 10 −4 m/s).