Preparation of TiB_2 coatings by electroplating in molten salt

作     者：LI Jun LI Bing DONG Zheng＇e 

作者机构：School of Resource and Environment Engineering East China University of Science and Technology Shanghai 200237 China School of Materials Engineering Shanghai University of Engineering Science Shanghai 200336 China School of Textile Xi＇an Institute of Science and Technology Xi＇an 710048 China 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2005年第24卷第3期

页      面：261-266页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：This work was financially supported by the National Natural Science Foundation of China (No. 50204006) 

主　　题：electrodeposition titanium diboride coatings molten salt 

摘      要：Titanium diboride （TIB2） coatings were prepared by electroplating in fluoride-chloride electrolytes （KF-KC1） containing K2T1F6 and KBF4 as the electrochemically-active components. An attempt was made to correlate the thermodynamic prediction and experimental observations. Thick, adherent, and uniform TtB2 coatings were obtained and the coating microhardness reaches the value of 33 GPa. The effects of the current density on the mechanical properties, structures, and morphologies of the coatings were studied. XRD analysis indicates that the preferred orientation of the coatings is （001）, which is in accordance with the prediction of the two-dimensional crystal nuclei theory. Thermodynamic prediction and experimental results show that some phases such as TixCy and BaCb are absent at the interface, which indicates the substrate and coatings bind mechanically or physically. Some cracks exist at the interface, which is attributed to the difference between the coefficients of thermal expansion of TiB2 and graphite.