High-temperature laser coatings of the ZrB2–MoSi2 system on graphite

Abstract

Coatings of the ZrB₂–MoSi₂ system on graphite (≤ 50 μm thick and 14–15 GPa in hardness) have been produced by pulse laser melting in air of two-layer powder coating with sublayers based on ZrB₂ with additions of ZrSi₂ and SiC. Different coating structures: eutectics of the ZrSiO₄–SiO₂ system based on zircon or a structure of micron-thick fibers of composition Zr(Mo)B₂ are formed depending on the sublayer composition, which controls the coating heat conductivity and accordingly, the crystallization rate of the bath of melt. The prospects of this line of investigations are the improvement of a laser technology of the deposition of high-temperature coating using continuous wave lasers.