Electrophoretic deposition of ZrB2 coatings in NaCl-KCl-AlF3 melt containing synthesized ZrB2 nanoparticles

A novel method for preparation of ZrB2 coatings has been proposed by combination of molten salt synthesis of ZrB2 nanoparticles and subsequent electrophoretic deposition of the as-synthesized ZrB2 nanoparticles in the same molten system in this paper. Nanoscale ZrB2 particles have been produced by borothermal reduction of ZrO2 in NaCl-KCl-AlF3 melt at 980 degrees C. Then electrophoretic deposition of the as-synthesized ZrB2 nanoparticles has been achieved in the resulting molten suspension at a reduced temperature of 900 degrees C, yielding relatively dense ZrB2 coatings on graphite substrates with a thickness of around 25 mu m. Moreover, the effect of different cell voltages ranging from 0.8 V to 1.4 V (i.e., electric field 0.4-0.7 V/cm) on the prepared ZrB2 coatings has been investigated. Finally, during the tests at 600 degrees C-800 degrees C in air, ZrB2 coatings deposited at a cell voltage of 1.2 V have exhibited good high-temperature oxidation resistance.

Automated summary

A novel method for preparing ZrB2 coatings by combining molten salt synthesis of ZrB2 nanoparticles and subsequent electrophoretic deposition has been proposed. Nanoscale ZrB2 particles were produced by borothermal reduction of ZrO2, and then deposited onto graphite substrates using electrophoretic deposition in the same molten system. The prepared ZrB2 coatings exhibited good high-temperature oxidation resistance.