Preparation and characterization of TiB2 coating by molten salt electrodeposition

Abstract:

The lifespan of carbon cathode is affected by the corrosion of molten salt and molten aluminum in aluminum reduction cell, and TiB₂ coating is an ideal cathode material for aluminum reduction cells.SIn this paper, TiB₂ coatings were electrodeposited on graphite in KF-KCl-K₂TiF₆-KBF₄molten salt at 700-800 _o^C with the current density of 0.4-0.7A.cm_-2^{. T}he coatings prepared at different current densities and temperatures were analyzed by XRD, SEM-EDS, surface roughness tester and adhesion tester.SThe results show that the obtained TiB₂ coating is uniform and coherent well to the graphite substrate. Increasing the current density and the electrolysis temperature can refine the grain size of the coating and improve the compactness of the coating. A TiB₂ coating thickness of 229 μm, the preferred orientation of <110>, the surface roughness of 14.85 μm, and the adhesion between the coating and graphite substrate of 6.39 MPa is prepared by electrodeposition under the optimum condition of 0.6 A.cm_-2 ^{and 750} ℃.