Compression plasma flows modification of surface layers in the system “Ti-Si”: Phase composition, structure and element redistribution

In the present study Ti5Si3/Si layers synthesized by compression plasma flows treatment (treatment time ~ 100 μs) of the system “titanium coating (1 μm) - silicon substrate” are studied. XRD, SEM and LAES were employed to characterize the phase composition, structure and elemental distribution of these layers. It has been found that plasma energy density (Q) dominates peculiarities of layer structure and elemental distribution. For Q < 5 J/cm2 layers of thickness up to 2 μm with diffusive element distribution form. For 5 J/cm2 < Q < 8 J/cm2 layers of thickness up to 10 μm with as convective as diffusive element distribution form. For Q > 8 J/cm2 layers of thickness up to 25 μm with convective element distribution form. Silicon dendrites grow in modified layer and eutectics Ti5Si3/Si is localized in interdendritic space. The mechanisms of structure formation and element redistribution are discussed in detail.