纳米掺杂对Al2O3＋13％TiO2等离子喷涂涂层耐蚀性能的影响

INFLUENCE OF DOPED NANOPARTICLES ON THE ANTICORROSION PERFORMANCE OF THE PLASMA SPRAYING Al_2O_3+13mass% TiO_2 COATINGS

利用大气等离子喷涂技术(APS),在45号钢基体上制备纳米掺杂5%～30%Al2O3+13%TiO2(质量分数)涂层,利用扫描电镜(SEM)、X射线衍射(XRD)等技术手段测定涂层组织结构及密度、孔隙度、通孔率等性能,在80℃、10%H2SO4溶液中对涂层进行浸蚀实验。结果表明,纳米掺杂提高了涂层在酸性介质中的鼓泡时间,而涂层从鼓泡到脱落所需时间与纳米含量无关。这是由于纳米掺杂使涂层密度提高,开孔率、通孔率降低,组织均匀性提高所致。建立了热喷涂涂层毛细管腐蚀模型,解释了纳米掺杂量对涂层失效的影响机理。

The coating samples of Al2O3＋13mass% TiO2 doped with 5% to 30% of nanoparticles were prepared on the substrate of steel 45 by air plasma spraying. The composition and structure, density, open hole percentage and pylome number were analyzed by SEM, XRD and other physical analysis methods. The samples were undergone corrosion in the medium of 10% H2SO4 aqueous solution at temperature 800 ℃. The results indicate that the bubbling time of coatings in the corrosive medium was increased with the increase of doped nanoparticles coneentration while the time from bubbling to spalling is independent of nanoparticles concentration. The improved performance of antieorrosion was resulted from the increase of coating density, the decrease of open hole percentage and pylome numbers. The capillapy corrosion model was established to analyze the influence of the doped nanopartieles on the coating failure.