Surface Characterization of Carbon Fibers by Atomic Force Microscopy: Roughness Quantification by Power Spectral Density

2017 ◽  
Vol 742 ◽  
pp. 447-456
Author(s):  
Bastian Brück ◽  
Thomas Guglhoer ◽  
Simon Haug ◽  
Christina Kunzmann ◽  
Michael Schulz ◽  
...  

The topography of a surface consists of structures of different length scales. The surface roughness caused by these structures plays a decisive role in interfacial properties. Atomic Force Microscopy (AFM) can be applied to measure the surface topography with great accuracy and thus facilitates roughness quantification. Here, however, the data reduction poses a challenge. In a conventional approach, surface roughness parameters are evaluated based on averaging height differences, which leads to values dominated by the largest height differences of the surface topography. To quantify contributions of smaller structures to the roughness, a previous study presented a tunable local background correction, which eliminates structures on a larger than selected scale. Therefore, this method only considers surface structures smaller than the chosen scale. A different approach to quantify surface roughness on all length scales covered by AFM measurements uses Fourier transformation of the surface topography to calculate the power spectral density, which describes the amplitudes of different contributing spatial frequencies.In the current study, a new approach based on power spectral density is used to quantify surface roughness parameters as a function of the length scale of contributions to the surface topography. This procedure allows a comprehensive characterization of surface roughness and an intuitive comparison of different surfaces.The usefulness of this method and its compatibility to local background correction is demonstrated by analyzing several commercially available carbon fibers with and without different fiber surface treatments.

1996 ◽  
Vol 440 ◽  
Author(s):  
A.G. Gilicinski ◽  
S.E. Beck ◽  
R.M. Rynders ◽  
D.A. Moniot

AbstractDespite the growing use of atomic force microscopy (AFM) for the measurement of silicon wafer microroughness, no generally accepted method has been developed to deal with issues around accuracy and reproducibility. We review problems that affect these AFM studies and demonstrate the effect of probe tip size on AFM microroughness data. Without knowledge of AFM probe tip geometry, it is impossible to quantitatively compare Ra or RMS microroughness data between different measurements. An experimental solution is to characterize tip sizes during imaging and compare data taken with similar size tips. While this will significantly improve quantitation, it is restrictive in that data taken with different size tips cannot be easily compared. We propose a solution to this problem in the use of power spectral density (PSD) to evaluate microroughness with a “cutoff frequency” at the lateral wavelength where tip effects begin to affect the accuracy of the microroughness measurement. An example of this approach is described


2010 ◽  
Vol 97-101 ◽  
pp. 4080-4083 ◽  
Author(s):  
Lei Geng ◽  
Hua Yan Zhong

The formation of WEDM surface is a complicated process. There are many factors which make machined surface topography have the characteristics of complex and irregular, and impact using performance of parts. The work investigated microscopic features of the WEDM surface topography based on power spectral density and fractal theory, and proposed power spectral density evaluation method of the WEDM surface. The fractal dimension of the WEDM surface was calculated by structure function method. The physical meaning of the fractal dimension of the WEDM surface was described. The result shows that topography of the WEDM surface exhibits strong fractal characteristics within a certain scale. The processing parameters and pulse power performance will affect the fractal dimension D. The fractal dimension D has a certain relationship with the surface roughness Ra. It is more reasonable to use the fractal dimension D as well as the surface roughness Ra together to evaluate WEDM surface quality.


1992 ◽  
Vol 280 ◽  
Author(s):  
H. Rojhantalab ◽  
M. Moinpour ◽  
N. Peter ◽  
M.L.A. Dass ◽  
W. Hough ◽  
...  

ABSTRACTChemically vapor deposited borophosphosilicate glass (BPSG) has been widely used in microelectronic device fabrication as interlayer dielectric film due to its excellent planarization, gettering and flow properties. With device geometry reducing to sub micron levels, there is an increasingly greater emphasis on detection and elimination of sub micron defects particularly on deposited film. In this paper, we report on the evaluation and characterization of the surface roughness of BPSG films of various thicknesses and film compositions deposited on Si substrates using the Atomic Force Microscopy (AFM). The effects of high temperature densification process on the surface roughness are presented. The defect detection capabilities of conventional laser-based particle counters with respect to the surface roughness of BPSG films are investigated.


2021 ◽  
Vol 153 ◽  
pp. 106632
Author(s):  
Hiro Tanaka ◽  
Kenta Okui ◽  
Yuki Oku ◽  
Hironori Takezawa ◽  
Yoji Shibutani

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1323
Author(s):  
Qing Zhang ◽  
Song Zhang

Surface topography and roughness significantly affect the functional properties of engineering parts. In this study, a mathematical model simulating the surface topography in end milling is presented and verified by milling experiments. The three dimensional (3D) surface amplitude parameters (arithmetic average deviation Sba and root mean square deviation Sq) of the milled surface were calculated by using the model and the effects of the product (p) and ratio (r) of radial depth of cut ae and feed per tooth fz on amplitude parameters were researched. To evaluate the lateral characteristics of the milled surface, one dimensional (1D) power spectral densities (PSD) along both feed and step-over direction were calculated and investigated. It was found that fz affects 1D PSD along both directions, whereas ae affects 1D PSD along the step-over direction. An angular spectrum, derived from the area power spectral density (APSD), was employed to research the spatial distribution of spectral energy on the milled surface. Furthermore, the influences of p and r on the PSD properties were researched. It was found that r is the significant factor that influences the direction of surface energy spectrum distribution.


2011 ◽  
Vol 54 (2) ◽  
pp. 116-128 ◽  
Author(s):  
Mark Paulus

This paper presents a set of experimental data comparing repetitive shock (RS) vibration, single-axis electrodynamic (ED) vibration, and multi-axis ED vibration. It was found that multi-axis testing is more severe than single-axis testing at the same level. In addition, weaknesses were found in the RS system at low frequency. Smoothing of the data or poor line resolution was also shown to change the overall severity of a test. A poor correlation was shown between the power spectral density (PSD) and the rate of natural frequency change (RFC) over a wide frequency shift. The change in natural frequency caused the initial PSD to be an ineffective indicator of test severity. Quantification of the severity of the test profile can be accomplished through characterization of the RFC.


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