A thorough experimental study was made of the processes determining formation of metastable surface alloys in a film-substrate system (Au-Ni, Sn-Cr) irradiated by laser pulses of nanosecond duration. The irradiation was performed in conventional conditions (on air) and, following the new method, through transparent overlay. A physical model of laser induced processes has been developed. The model predicts an increases of the depth of the melt, elevation of the liquid-phase temperature, rise of the diffusion speed of atoms in the liquid phase, and decrease of the cooling rate of the alloy during irradiation through the transparent overlay.
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