Effect of anodized layer thickness on fatigue behavior of magnesium alloy
Effect of anodized layer thickness on fatigue behavior of magnesium alloy
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DOI：
10.1016/j.msea.2007.04.078
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发表时间：
2008-02-15
期刊：
影响因子：
6.4
通讯作者：
Koike, Toshikatsu
中科院分区：
文献类型：
--
作者：
Khana, Sabrina Alam;Miyashita, Yukio;Koike, Toshikatsu
阳极氧化工艺已被用作一种有效的方法，以保护底层材料免受腐蚀环境的影响。在本研究中，由于防腐能力取决于阳极氧化层的厚度和质量，所以使用15μm、5μm和1μm三种不同的阳极氧化层厚度，研究了阳极氧化层厚度对AM60镁合金疲劳性能的影响。具有15μm厚阳极氧化层的试样在基体和阳极氧化层之间呈现出粗糙且不规则的界面。在阳极氧化层中还观察到许多缺陷。但是当阳极氧化层的厚度从15μm减少到5μm再到1μm时，界面粗糙度趋于降低。界面粗糙度的作用反映在三组试样的疲劳强度上，其中界面最光滑的试样，即1μm厚的阳极氧化试样，在三组中表现出最高的疲劳强度。对于具有15μm厚阳极氧化层的试样，疲劳极限处的ΔK估计值几乎等于ΔKₜₕ（约为0.86MPa√m），而对于具有5μm和1μm厚阳极氧化层的试样，估计的ΔK值远低于ΔKₜₕ，此时应将初始裂纹视为小裂纹。针对当前三种阳极氧化层厚度的著名的北川 - 高桥图表明，阳极氧化层厚度最好小于5μm。（C）2007爱思唯尔有限公司。保留所有权利。
The process of anodizing has been adopted as an effective way to protect underlying material from corrosive environments. In the present study, since the corrosion protection ability would depend on thickness and quality of the anodized layer, effect of anodized layer thickness on fatigue behavior of AM60 magnesium alloy was investigated using three different anodized layer thicknesses of 15, 5 and 1 mu m. The specimen with 15 mu m thick anodized layer showed rough and irregular interface between substrate and anodized layer. Many defects were also observed in the anodized layer. But as the thickness of anodized layer was reduced from 15 to 5 to 1 mu m, interface roughness was tended to be diminished. The role of interface roughness was reflected in the fatigue strength of three groups of specimens, where the specimen with the smoothest interface, 1 mu m thick anodized specimen, showed the highest fatigue strength among the three groups. For the specimen with 15 mu m thick anodized layer, the estimated value of Delta K at fatigue limit was almost equal to Delta K-th (approximate to 0.86 MPa root m) while for the specimens with 5 and 1 mu m thick anodized layers the estimated Delta K values were well below the Delta K-th, where the initial crack should be considered as small crack. Well-known Kitagawa-Takahashi diagram for the present three kinds of anodizing layer thickness suggested that the anodizing layer thickness would be preferred less than 5 mu m. (C) 2007 Elsevier B.V. All rights reserved.