Fabrication and characterization of aluminide coating on V–5Cr–5Ti by electrodeposition and subsequent heat treating
Fabrication and characterization of aluminide coating on V–5Cr–5Ti by electrodeposition and subsequent heat treating
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DOI：
10.1016/j.ijhydene.2016.04.067
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发表时间：
2016-06
影响因子：
7.2
通讯作者：
Xuexing Peng;Guikai Zhang;Feilong Yang;X. Xiang;L. Luo;C. Chen;Xiaolin Wang
中科院分区：
文献类型：
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作者：
Xuexing Peng;Guikai Zhang;Feilong Yang;X. Xiang;L. Luo;C. Chen;Xiaolin Wang
在V合金表面制备Al_xVy涂层是V-Al/Al_2 O_3防氚渗透膜的关键步骤。我们首次尝试通过电化学铝沉积（ECA）和热处理两步工艺在V-5Cr-5 Ti上制备铝化物涂层。在室温下，在8 - 32 mA/cm 2的电流密度下，从AlCl 3 -1-乙基-3-甲基-咪唑氯化物（AlCl 3-EMIC）离子液体中进行Al沉积。在电流密度为20 mA/cm 2的条件下，V-5Cr-5 Ti合金表面获得了均匀、结合力良好的铝镀层，沉积速率可达21 μm/h。然后在流动的氩气中加热铝涂层，形成铝化物涂层。铝化物涂层呈双层或几乎单层结构，其厚度分别随温度、时间和铝涂层厚度的增加而增加。扩散初期涂层的主相为Al 3（V，Cr，Ti），随后逐渐转变为Al 8（V，Cr，Ti）5，其次为V（Al，Cr，Ti）固溶体，双层结构转变为单层结构。Al_8（V，Cr，Ti）_5的均匀层是进一步选择性氧化的合适的铝化物层。获得了最佳渗铝工艺条件和Al 8（V，Cr，Ti）5的生长动力学。
Preparation of aluminide coatings, AlxVy, is a key step for the formation of V-Al/Al2O3as tritium permeation barrier (TPB) on V alloys. We firstly attempted to process aluminide coatings on V–5Cr–5Ti by a two-step process of electrochemical Al deposition (ECA) and heat treatment. Al deposition from AlCl3-1-ethyl-3-methyl-imidazolium chloride (AlCl3-EMIC) ionic liquid was performed at room temperature, with current density varying from 8 to 32 mA/cm2. Homogeneous and well adherent Al coatings on V–5Cr–5Ti were obtained by galvanostatic electrodeposition at 20 mA/cm2, with the deposition rates up to 21 μm/h. And then Al-coated specimens were heated in flowing Argon gas, forming aluminide coatings. The aluminide coatings exhibited a double-layer or almost a single-layer structure, and their thickness increased with temperature, time and Al-coating thickness, respectively. Main phase of coatings was Al3(V, Cr, Ti) at initial diffusion stage, and then gradually transformed into Al8(V, Cr, Ti)5, and next to V(Al, Cr, Ti) solid solution, with double-layer structure transforming into single-layer structure. The homogenous layer of Al8(V, Cr, Ti)5is the appropriate aluminide for further selective oxidation. The optimum aluminized conditions and growth kinetics of Al8(V, Cr, Ti)5were obtained.