Electrodeposition of Al-W Alloys in AlCl₃-NaCl-KCl Molten Salt Containing WCl₄

To form Al-W alloys for high temperature oxidation resistance components, molten salt electrolysis was carried out in an AlCl₃-NaCl-KCl melt containing WCl₄ at 423 K. The voltammogram showed two cathodic waves at 1.1 V and 0.5 V vs. Al/Al(III), which may correspond to the reduction from W(IV) to W(III) and from W(III) to tungsten metal, respectively. Electrodeposits of Al and W were obtained in the range from -0.05 to 0.4 V and the highest concentration of W in the electrodeposit was 95 at% at 0.4 V. With increasing W content in the alloy, the morphology of the electrodeposits became more powdery and the particle size smaller.