哈氏合金表面粗糙度AFM测量中扫描尺度等问题研究

Investigations on Scan Scale and Other Issues of AFM Measurements for Surface Roughness of Hastelloy C276

哈氏合金HastelloyC276是一种被广泛应用的镍基合金，具有机械性能优良、抗腐蚀能力强等优势，在第二代高温超导导线的离子柬辅助沉积（IBAD）技术路线中被用作金属基底，因此其表面抛光与粗糙度测量受到了广泛重视。哈氏合金的表面形貌和粗糙度测量一般采用原子力显微镜（AFM）方法，在该方法中扫描尺度对测量结果具有显著的影响。本研究对两个分别进行了电化学抛光和机械抛光的哈氏合金带材短样，在1N70μm范围内选取不同扫描尺度进行了AFM测量，从而对其表面形貌获得了全面的了解，并发现其表面粗糙度随着扫描尺度的变大出现了明显的增大，文中还在不同扫描尺度下考察了电化学抛光与机械抛光的作用区别。此外，本研究中分析了AFM图像的后处理中flatten阶数的影响，对从AFM图像中分割出小尺度局域计算粗糙度的方法进行了改进，并讨论了AFM测量粗糙度的可重复性问题。通过这些研究，对表面粗糙度的AFM测量方法在全面性和有效性方面进行了完善，提出了粗糙度描述时有必要给出的相关参数。

Hastelloy C276 was a widely used nickel-based alloy, due to its advantages of mechanical and anti-corrosion properties. In the fabrication of second generation high temperature superconducting wires via the ion beam assisted deposition （IBAD） route, Hastel- loy served as the metallic substrate, therefore, the polishing and roughness measurements of its surface were concerned worldwide. A- tomic force microscopy （AFM） was generally applied to characterize the surface morphology and roughness of Hastelloy. The scan scale played an important role in AFM measurements. In this study, two Hastelloy tape samples, electro pohshed and mechanically polished respectively, were measured at different scan scales ranging from 1 to 70 μm. An overall understanding of their surface morphologies could be achieved, and the surface roughness was found to increase with the scan scale. The differences of electro polishing and me- chanically polishing were carried out to consider the scale variation. Besides, the effect of flatten order in the post processing of AFM images was analyzed. The roughness calculation of smaller parts divided out of AFM images was modified. And the repeatability of AFM measurement for surface roughness was also discussed. Some necessary principles could be proposed for the roughness measure- ment by AFM based on above investigations, improving the comprehensiveness and effectiveness.