Wettability of TiB2-based ceramics by NdF3-LiF-Nd2O3 melt was studied using sessile drop technique in this paper. Wetting experiment was carried out under inert atmosphere at 1050 °C. Chemical reactions which occurred on the solid-liquid interface and solid-gas interface during wetting process were discussed by thermodynamic calculations combined with X-ray diffraction(XRD) patterns. Micromorphology and element distribution of fracture surface at the interfacial region of solid/liquid system were analyzed by scanning electron microscope(SEM) equipped with energy dispersive spectrometry(EDS) . Contact angles of the drop were determined as a function of time in order to describe the wetting process,and wetting phenomenon was interpreted from a viewpoint of interface structure. The results showed that wetting was a dynamic wetting process with characteristics of reactive wetting. Penetration and oxidization phenomena during the experiment had great effect on wetting process.
Electrochemical deposition and nucleation of aluminum on tungsten electrode from AlCl_3-NaCl melts were studied by cyclic voltammetry,chronopotentiometry and chronoamperometry.Cyclic voltammetry and chronopo- tentiometry analyses showed that Al(Ⅲ) was reduced at 200℃in two consecutive steps in an electrolyte of molten AlCl_3-NaCl system with a composition 52:48 molar ratio.The current-time characteristics of nucle- ation aluminum on tungsten showed a strong dependence on overpotentials.Chronoamperometry showed that the deposition process of aluminum on tungsten was controlled by an instantaneous nucleation with a hemispherical diffusion-controlled growth mechanism.The results could lead to a better understanding of the AlCl_3-NaCl melt system that has technological importance in electrodeposition of metals as well as in rechargeable batteries.
Zhaowen WANG Hongmin KAN Zhongning SHI Bingliang GAO Yungang BAN Xianwei HU
