Electrochemical Dissolution Behaviors of Scrap Superalloys in Different Electrolytes

Owing to the demand for strategic metals, the dissolution of scrap superalloys is imperative for their recycling. This study investigates the electrochemical dissolution process of superalloys in different electrolytes. The results indicate that the dissolution rate of the samples is significantly emulative in organic electrolyte at current densities greater than 0.7 A cm −2 . The dissolution behavior of the sample in aqua regia electrolyte can be classified as dissolution of the oxidation layer, formation of the anode product layer, and formation of the Cr-rich hindered-dissolution layer. While in organic electrolyte, the dissolution behavior can be partitioned as dissolution of the oxidation layer, formation of the porous Cr-rich hindered-dissolution layer, formation of dissolved pores, and detachment of the porous Cr-rich hindered-dissolution layer. Therefore, the formation of dissolved pores and detachment of the porous Cr-rich hindered-dissolution layer can effectively reduce the electrolytic resistance and the diffusion resistance in the electrolyte.