(西安建筑科技大学 陕西省冶金工程技术研究中心，陕西省黄金与资源重点实验室，西安 710055)
摘 要: 选用硼酸钠-氯化钙体系为电解质，采用熔盐电解法在钛表面渗硼，研究熔盐温度及渗硼时间对渗层物相、形貌及渗层厚度的影响，并对渗层生长动力学进行了分析。利用XRD对渗硼试样表面进行物相分析，利用扫描电镜(SEM)观察渗硼试样的断面形貌并采用能谱(EDS)进行元素分析。结果表明：在温度为1153~1293 K、电流密度为500 A/m2，通电15~60 min的条件下，Ti表面得到的硼化物渗层上层是均匀致密的TiB2，下层是嵌入基体的针状TiB；在1293 K下渗硼60 min后，所得渗层中TiB2厚度约为8.4 μm。根据TiB2渗层厚度随时间的变化关系，计算出渗层在1193、1243和1293 K的生长速率常数分别为5.85×10-15、1.24×10-14和2.10×10-14 m2/s，TiB2渗层生长激活能为152.02 kJ/mol。
关键字: 熔盐电解；渗硼；TiB2；钛；生长动力学
（Shaanxi Engineering Research Center of Metallurgy, Shaanxi Key Laboratory of Gold and Resources, Xi’an University of Architecture and Technology, Xi’an 710055, China）
Abstract:The molten salt electrolysis method was applied for boronizing on titanium surface using the Na2B4O7-CaCl2 composition as electrolyte. The effects of salt temperature and boriding time on the phase composition, microstructure and the thickness of the TiB2/TiB layer were investigated and the growth kinetics of the boride layer was analyzed. XRD, SEM and EDS means were applied to analyze the phase composition, microstructure and morphology, element content of the borides layer, respectively. The results show that, when the experiment is carried out at 1153~1293 K with the current density of 500 A/m2 and boriding time of 15~60 min, the boride layers consist of a homogeneous and dense TiB2 on the top and TiB whiskers penetrating into the substrate. The thickness of TiB2 is 8.4 μm when boriding at 1293 K for 60 min. The growth kinetics of the boride layer was studied by analyzing the relationship of the thickness of TiB2 layer versus time by mathematic method, and it is calculated that the constant values for the TiB2 layer at 1193，1243 and 1293 K are 5.85×10-15, 1.24×10-14 and 2.10×10-14 m2/s, respectively, and the activation energy for the growth of the TiB2 layer is determined to be 152.02 kJ/mol.
Key words: molten salt electrolysis; boriding; TiB2; titanium; growth kinetics
