Electrodeposition of silicon onto copper substrate from KF-KCl-KI-K2SiF6 melt

The electrochemical behavior of Si4+ deposited onto the Cu substrate, in comparison with one onto C substrate, in the KF-KCl-KI-K2SiF6 melt was investigated by the cyclic voltammetry at 993 K. It was found, that the electro reduction of silicon on the Cu substrate proceeds with formation of the Cu-Si alloy (silicon bronze). The electrolysis conditions were determined and the silicon bronze coatings were synthesized by electrolysis in the KF-KCl-KI-K2SiF6 melt. The surface of deposits was examined by the electron microsccopy with EDS analysis. The deposits contained only copper and silicon. The microhardness of the coatings achieved 1618 HV. The microhardness of the obtained films was tested in air during one month: it decreased from 1618 to 380 HV.