Solidification structures on carbon materials surface-melted by repetitive laser pulses

摘要

The solidification morphology of carbon materials surface-melted by laser radiation at atmospheric pressure is studied. Electron microscopy results indicate that melt solidification is accompanied by the formation of surface microstructures, presumably due to the Rayleigh-Taylor instability in the molten carbon. The instability increment and surface tension coefficient of molten carbon are estimated, and the penetration of carbon vapour into the melt during one laser pulse is examined using numerical simulation.