Electrodeposition of Al–Pt alloys using constant potential electrolysis in AlCl3–NaCl–KCl molten salt containing PtCl2

To form Al–Pt alloys for high temperature coatings, molten salt electrolysis was attempted with an AlCl3–NaCl–KCl molten salt containing PtCl2 at 448 K. The voltammogram showed cathodic reduction of Pt ions to start at a potential of 1.4 vs. Al/Al(III) in the molten salt. Deposition of pure Pt was possible at 1.2 V and there was co-deposition of Al and Pt at potentials more negative than 1.0 V. The co-deposit was a mixture of intermetallic compounds of AlPt2 or AlPt3. The ratio of the Pt in the electrodeposits decreased with increasingly negative potentials from 100 at.% at 1.2 V to 25 at.% at 0.0 V.