(西安建筑科技大學(xué) 陜西省冶金工程技術(shù)研究中心，陜西省黃金與資源重點實驗室，西安 710055)
摘 要: 選用硼酸鈉-氯化鈣體系為電解質(zhì)，采用熔鹽電解法在鈦表面滲硼，研究熔鹽溫度及滲硼時間對滲層物相、形貌及滲層厚度的影響，并對滲層生長動力學(xué)進行了分析。利用XRD對滲硼試樣表面進行物相分析，利用掃描電鏡(SEM)觀察滲硼試樣的斷面形貌并采用能譜(EDS)進行元素分析。結(jié)果表明：在溫度為1153~1293 K、電流密度為500 A/m2，通電15~60 min的條件下，Ti表面得到的硼化物滲層上層是均勻致密的TiB2，下層是嵌入基體的針狀TiB；在1293 K下滲硼60 min后，所得滲層中TiB2厚度約為8.4 μm。根據(jù)TiB2滲層厚度隨時間的變化關(guān)系，計算出滲層在1193、1243和1293 K的生長速率常數(shù)分別為5.85×10-15、1.24×10-14和2.10×10-14 m2/s，TiB2滲層生長激活能為152.02 kJ/mol。
關(guān)鍵字: 熔鹽電解；滲硼；TiB2；鈦；生長動力學(xué)
（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
