Growth, microstructure and mechanical properties of microarc oxidation coatings on titanium alloy in phosphate-containing solution
Growth, microstructure and mechanical properties of microarc oxidation coatings on titanium alloy in phosphate-containing solution
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DOI：
10.1016/j.apsusc.2004.03.231
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发表时间：
2004-06-30
影响因子：
6.7
通讯作者：
Guo, LX
中科院分区：
文献类型：
--
作者：
Wang, YM;Lei, TQ;Guo, LX
在(NaPO3)(6)-NaF-NaAlO2溶液中，采用恒流微弧氧化法在Ti6Al4V合金表面制备了陶瓷涂层。用扫描电子显微镜和X射线衍射仪研究了涂层的生长、显微组织和物相组成。随着处理时间的延长，涂层的生长由快变慢，并伴随着外观的逐渐粗化。同时，也发生了锐钛矿向金红石的相变。在附近的放电通道中，水合多聚磷酸铝通过高温热分解生成晶态AlPO4。阶梯电流区使涂层结构可控。通过纳米压痕和剪切试验分别测定了涂层厚度方向的力学性能分布和结合强度。硬度和弹性模量随涂层厚度的变化曲线相似：致密区保持较高的值(5.5和69.1 GPA)，松散区最终下降到较低的值(5.1和65.6 GPA)。基材/涂层界面结合强度约为40 Mpa。(C)2004爱思唯尔B.V.保留所有权利。
Ceramic coatings were fabricated by microarc oxidation in galvanostatic regime on Ti6Al4V alloy in (NaPO3)(6)-NaF-NaAlO2 solution. The growth, microstructure and phase composition of coatings were investigated using scanning electron microscope and X-ray diffraction. With increasing treatment duration, coating growth varies from rapidness to tardiness accompanied by gradually roughening in appearance. Meanwhile, phase transformation of anatase to rutile occurs. The crystalline AlPO4 is involved in the coatings via high-temperature thermolysis of hydrated aluminium polyphosphates in the nearby discharging channels. The stepped current regime enables coating structure to be controllable. The mechanical properties distribution across the coating thickness and the adhesion strength were determined by nanoindentation and shear test, respectively. A similar evolution profile of hardness and elastic modulus across the coating thickness is found: remaining high values (5.5 and 69.1 GPa) in the compact region before finally declining to low values (5.1 and 65.6 GPa) in the looser region. The adhesion strength of substrate/coating interface is about 40 MPa. (C) 2004 Elsevier B.V. All rights reserved.