Fractal-Based Characterization of Surface Texture

1992 ◽  
Vol 35 (3) ◽  
pp. 37-44
Author(s):  
Ken Grosser ◽  
Stephen Chesters ◽  
Hwa-Chi Wang ◽  
Gerhard Kasper

The surface roughness of high purity gas system distribution materials is a matter of concern for many critical manufacturing processes. Control of this roughness is thus much in demand and requires a sensitive measurement method. A refined fractal-based characterization is presented as a possible solution. Test data that use this method to compare various surface finishes and correlate roughness with surface cleanability are offered with explanations. This could become an effective quality assurance tool in those applications where surface roughness is important.

1993 ◽  
Vol 115 (1) ◽  
pp. 131-134 ◽  
Author(s):  
V. W. Antonetti ◽  
T. D. Whittle ◽  
R. E. Simons

An approximate thermal contact conductance correlation which does not depend upon the surface asperity slope was developed. Published surface texture data for 65 specimens were used to establish a relationship between the average roughness and the RMS asperity slope, which was then used to develop a new approximate thermal contact conductance correlation. The investigation was conducted for a range of surface roughness typical of contacting surfaces. Comparison to limited test data and to 2080 simulated contact joints, indicates the new approximate thermal contact conductance correlation has an expected RMS error of approximately 23 percent.


Author(s):  
Akhil V ◽  
Arunachalam N ◽  
Raghav G ◽  
Sivasrinivasu Devadula

The Selective Laser Melting (SLM) process based additive manufacturing has wide applications in medical, aerospace, defense, and automotive industries. To qualify the components for certain tribological applications, the characterization of surface texture is very important. But the applicability of traditional methods and parameters to characterize the surface texture were under evaluation. As the nature manufacturing the components were very different and complex, the unconventional surface characterization methods also under evaluation to reveal much more meaningful information. This study demonstrates the surface characterization of Ti-6Al-4V SLM components using fractal analysis of the surface images. The computed fractal dimension using the Fourier transform method showed a strong correlation of more than 0.8 with the measured 3D surface roughness parameters. The change in anisotropic nature of the surface images with the process parameter variation is studied and found that the surface textures showed a weaker anisotropic nature at lower laser power ranges, high scanning speed, and high hatch distance values. The lacunarity analysis is carried out using the gliding box algorithm to study the homogeneity nature of the surface texture and found that the surface texture is more homogeneous at higher surface roughness conditions. The study results can be utilized for the development of a quick, low-cost surface monitoring system in real-time for additive manufacturing industries.


Author(s):  
V. C. Kannan ◽  
S. M. Merchant ◽  
R. B. Irwin ◽  
A. K. Nanda ◽  
M. Sundahl ◽  
...  

Metal silicides such as WSi2, MoSi2, TiSi2, TaSi2 and CoSi2 have received wide attention in recent years for semiconductor applications in integrated circuits. In this study, we describe the microstructures of WSix films deposited on SiO2 (oxide) and polysilicon (poly) surfaces on Si wafers afterdeposition and rapid thermal anneal (RTA) at several temperatures. The stoichiometry of WSix films was confirmed by Rutherford Backscattering Spectroscopy (RBS). A correlation between the observed microstructure and measured sheet resistance of the films was also obtained.WSix films were deposited by physical vapor deposition (PVD) using magnetron sputteringin a Varian 3180. A high purity tungsten silicide target with a Si:W ratio of 2.85 was used. Films deposited on oxide or poly substrates gave rise to a Si:W ratio of 2.65 as observed by RBS. To simulatethe thermal treatments of subsequent processing procedures, wafers with tungsten silicide films were subjected to RTA (AG Associates Heatpulse 4108) in a N2 ambient for 60 seconds at temperatures ranging from 700° to 1000°C.


2021 ◽  
Vol 272 ◽  
pp. 121947
Author(s):  
Calypso Chadfeau ◽  
Safiullah Omary ◽  
Essia Belhaj ◽  
Christophe Fond ◽  
Françoise Feugeas

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1376
Author(s):  
Alex Quok An Teo ◽  
Lina Yan ◽  
Akshay Chaudhari ◽  
Gavin Kane O’Neill

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1317
Author(s):  
Michal Skrzyniarz ◽  
Lukasz Nowakowski ◽  
Edward Miko ◽  
Krzysztof Borkowski

The shaping process of surface texture is complicated and depends on many factors and phenomena accompanying them. This article presents the author’s test stand for the measurement of relative displacements in a tool–workpiece system during longitudinal turning. The aim of this study was to determine the influence of edge radius on the relative displacement between the tool and workpiece. The cutting process was carried out with inserts with different edge radii for X37CrMoV5-1 steel. As a result of the research, vibration charts of the tool–workpiece system were obtained. In the range of feed 0.03–0.18 mm/rev, the values of the standard deviation of relative displacements in the x-axis were obtained in the range of 0.36–0.78 μm for the insert with an edge radius of rn = 48.8 μm. As a result of the work, it was determined that for the feed value of 0.12 mm/rev for all inserts, the relative displacements are the smallest. As the final effect, the formula for forecasting the Ra roughness parameter was presented.


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