In developing wettable TiB₂-based cathodes for Al production, the main problem encountered for decades is the difficulty to sinter or melt this refractory material. Here, suspension plasma spray (SPS) is used as this process makes it possible to use micrometric TiB₂ particles to favor a high heat transfer per particle. In addition, an argon gas shield is used to protect the inflight TiB₂ particles from oxidation with air during spraying. Our results confirm the efficiency of the argon shroud to limit TiB₂ oxidation when compared with a TiB₂ coating obtained without shroud. The SPS TiB₂ coatings show a good adhesion to the graphite substrate. However, their high porosity indicates an insufficient TiB₂ melting during the spraying, suggesting that the transit time spent by the TiB₂ particles in the plasma is too short. The SPS TiB₂ coatings present a good wettability for molten Al. However, Al infiltration through the porous coating results in the direct contact of molten Al with the graphite substrate, which may be detrimental for its mechanical integrity.

在开发用于铝生产的可湿性 TiB ₂基阴极时，几十年来遇到的主要问题是难以烧结或熔化这种耐火材料。在这里，使用悬浮等离子喷涂 (SPS)，因为该工艺可以使用微米级 TiB ₂颗粒来促进每个颗粒的高传热。此外，使用氩气保护层来保护飞行中的 TiB ₂颗粒在喷涂过程中不会被空气氧化。我们的结果证实了当与没有护罩的情况下获得的 TiB ₂涂层相比时氩护罩限制 TiB ₂氧化的效率。SPS TiB ₂涂层对石墨基材显示出良好的附着力。然而，它们的高孔隙率表明在喷涂过程中TiB ₂熔化不足，表明 TiB ₂颗粒在等离子体中的传输时间太短。SPS TiB ₂涂层对熔融铝具有良好的润湿性。然而，铝渗入多孔涂层导致熔融铝与石墨基材直接接触，这可能对其机械完整性有害。