Comprehensive topography characterization of polycrystalline diamond coatings
Comprehensive topography characterization of polycrystalline diamond coatings
复制标题
DOI：
10.1088/2051-672x/abe71f
复制
发表时间：
2021-03-01
影响因子：
2.7
通讯作者：
Jacobs, Tevis D. B.
中科院分区：
文献类型：
--
作者：
Gujrati, Abhijeet;Sanner, Antoine;Jacobs, Tevis D. B.
金刚石涂层的表面形貌对附着力、摩擦、磨损和生物相容性等表面性能有很大影响。然而，传统的测量方法只捕捉单一的长度尺度，阻碍了对多尺度地形及其对特性的影响的理解。在这里，四种不同的聚晶金刚石涂层用透射电子显微镜进行了表征，以评估其粗糙度到亚纳米级。然后，使用功率谱密度(PSD)与传统方法(触针轮廓术和原子力显微镜)相结合来表征所有尺度的地形。结果表明，测量所有长度尺度上的地形是至关重要的，特别是因为它们的PSD彼此交叉，因此在较大尺度上较粗糙的表面可能在较小尺度上较光滑，反之亦然。此外，这些测量揭示了多尺度地形与颗粒尺寸之间的关系，在平均颗粒尺寸处和略低于平均颗粒尺寸处具有特征的标度行为，而在其他长度尺度上具有自仿射类分形粗糙度。在小的(亚颗粒)尺度上，未抛光的表面表现出一种常见的形式的残余粗糙度，本质上是自仿射的，但很难用传统方法检测到。这种从原子尺度到宏观尺度捕捉地形的方法被称为综合地形表征，所有这些表面的地形数据都已提供给实验者和理论家进行进一步的分析。科学地说，这项调查确定了聚晶金刚石材料的四个特征地形尺度区域。
The surface topography of diamond coatings strongly affects surface properties such as adhesion, friction, wear, and biocompatibility. However, the understanding of multi-scale topography, and its effect on properties, has been hindered by conventional measurement methods, which capture only a single length scale. Here, four different polycrystalline diamond coatings are characterized using transmission electron microscopy to assess the roughness down to the sub-nanometer scale. Then these measurements are combined, using the power spectral density (PSD), with conventional methods (stylus profilometry and atomic force microscopy) to characterize all scales of topography. The results demonstrate the critical importance of measuring topography across all length scales, especially because their PSDs cross over one another, such that a surface that is rougher at a larger scale may be smoother at a smaller scale and vice versa. Furthermore, these measurements reveal the connection between multi-scale topography and grain size, with characteristic scaling behavior at and slightly below the mean grain size, and self-affine fractal-like roughness at other length scales. At small (subgrain) scales, unpolished surfaces exhibit a common form of residual roughness that is self-affine in nature but difficult to detect with conventional methods. This approach of capturing topography from the atomic- to the macro-scale is termed comprehensive topography characterization, and all of the topography data from these surfaces has been made available for further analysis by experimentalists and theoreticians. Scientifically, this investigation has identified four characteristic regions of topography scaling in polycrystalline diamond materials.