Preparation of a SiCf/Al composite precursor by electrochemical deposition in a LiCl–KCl–AlCl3 molten salt

Abstract

The preparation of suitable SiC fiber (SiCf)/Al precursors is crucial for the fabrication of SiCf-strengthened Al alloys. In this work, a SiCf/Al precursor was prepared by pulse current deposition in a molten LiCl–KCl–AlCl3 melt. The electrochemical deposition of Al3+ was separately investigated on the Mo wire, Cu wire, SiCf, and Cu-coated SiCf electrodes. The intermediate Cu layer can eliminate the Li generated by the underpotential deposition on the carbon layer outside SiCf. In addition, open circuit chronopotentiometry was performed to confirm the reduction processes of Al3+ on the Cu wire and Cu-coated SiCf, and the results indicate that Al3+ exhibits similar reduction processes on the two electrodes. The deposited Al layer possibly formed Al–Cu alloys with the intermediate Cu layer on SiCf, which was beneficial to the connection between the Al layer and SiCf substrate. Scanning electron microscopy was employed to investigate the morphology and microstructure of the prepared SiCf/Al fiber. After the pulse current was optimized, a compact and even layer of Al was deposited on SiCf.