Cold spray deposition of mechanically alloyed Cu-Ni-Fe material for application as inert anodes for aluminum production

Abstract

Cold spray deposition was evaluated for the production of inert anodes for Al electrolysis from mechanically alloyed Cu-Ni-Fe powders. Cu65Ni20Fe15 (in wt. %) alloy was first prepared from elemental Cu, Ni, Fe powders using an attritor. After 40 h of milling, a nanocrystalline and monophasic Cu(Ni,Fe) solid solution was formed. It was shown that the particle size of the milled powder can be controlled with the addition of stearic acid to the initial powder mixture. In a second step, the cold spray parameters (pressure and temperature of the carrier N2 gas) were optimized in order to maximize the impact velocity of the Cu65Ni20Fe15 particles on the substrate. Then, thick (1100 μm), dense (porosity of 1–2 %) and adherent (adhesion strength of 15 MPa) coatings of Cu65Ni20Fe15 on C63000 substrate (nickel aluminium bronze alloy) were produced. No structural change of the Cu65Ni20Fe15 alloy was observed during cold spray processing.