TiB2涂层熔盐电沉积制备与表征

Preparation and characterization of TiB2 coating by molten salt electrodeposition

摘要:

炭阴极在铝电解槽中受熔盐和铝液腐蚀而影响寿命,而TiB₂涂层是铝电解槽理想的阴极材料。本文以石墨为基体,在KF-KCl-K₂TiF₆-KBF₄熔盐中以0.4-0.7A.cm_-2^{电流密度、}700-800℃温度电沉积TiB₂涂层,通过XRD衍射仪、SEM-EDS、表面粗糙度测量仪及附着力测试仪对不同电流密度和温度下制备的涂层进行表征。结果表明：在石墨基体上可以得到均匀连贯的TiB₂涂层；增大电流密度、降低电解温度可以细化涂层晶粒,提高涂层致密性；在0.6 A.cm_-²、750℃最优电沉积条件下制得的TiB₂涂层的厚度为229 μm,择优取向为<110>,表面粗糙度为14.85 μm,涂层与石墨基体的结合力为6.39 MPa。

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} ℃.