scholarly journals Machine learning for multi-dimensional optimisation and predictive visualisation of laser machining

Author(s):  
Michael D. T. McDonnell ◽  
Daniel Arnaldo ◽  
Etienne Pelletier ◽  
James A. Grant-Jacob ◽  
Matthew Praeger ◽  
...  

AbstractInteractions between light and matter during short-pulse laser materials processing are highly nonlinear, and hence acutely sensitive to laser parameters such as the pulse energy, repetition rate, and number of pulses used. Due to this complexity, simulation approaches based on calculation of the underlying physical principles can often only provide a qualitative understanding of the inter-relationships between these parameters. An alternative approach such as parameter optimisation, often requires a systematic and hence time-consuming experimental exploration over the available parameter space. Here, we apply neural networks for parameter optimisation and for predictive visualisation of expected outcomes in laser surface texturing with blind vias for tribology control applications. Critically, this method greatly reduces the amount of experimental laser machining data that is needed and associated development time, without negatively impacting accuracy or performance. The techniques presented here could be applied in a wide range of fields and have the potential to significantly reduce the time, and the costs associated with laser process optimisation.

2005 ◽  
Vol 128 (2) ◽  
pp. 345-350 ◽  
Author(s):  
Y. Feldman ◽  
Y. Kligerman ◽  
I. Etsion ◽  
S. Haber

Microdimples generated by laser surface texturing (LST) can be used to enhance performance in hydrostatic gas-lubricated tribological components with parallel surfaces. The pressure distribution and load carrying capacity for a single three-dimensional dimple, representing the LST, were obtained via two different methods of analysis: a numerical solution of the exact full Navier-Stokes equations, and an approximate solution of the much simpler Reynolds equation. Comparison between the two solution methods illustrates that, despite potential large differences in local pressures, the differences in load carrying capacity, for realistic geometrical and physical parameters, are small. Even at large clearances of 5% of the dimple diameter and pressure ratios of 2.5 the error in the load carrying capacity is only about 15%. Thus, for a wide range of practical clearances and pressures, the simpler, approximate Reynolds equation can safely be applied to yield reasonable predictions for the load carrying capacity of dimpled surfaces.


2015 ◽  
Vol 2015 (0) ◽  
pp. _J1130201--_J1130201-
Author(s):  
Fumihiro ITOIGAWA ◽  
Hiroki KIYOTA ◽  
Takashi NAKAMURA ◽  
Kei-ichi KAWATA

2011 ◽  
Vol 321 ◽  
pp. 234-239 ◽  
Author(s):  
Xxx Sedao ◽  
Thierry Sarnet ◽  
José Luis Hernandez ◽  
Malte Schulz Ruhtenbuerg ◽  
Stephan Krantz

Laser grooving is an existing industrial solution for solar cell junction isolation. However there is still plenty room to improve this process. Potential approach includes choosing proper laser wavelength, tuning laser pulse width and laser focus beam profile, etc. We have recently investigated laser edge isolation of crystalline silicon solar cells using an ultra-short pulse laser. In this study we carried out isolation test using the same laser with a top-hat beam profile. A comparative study between isolation using top-hat and Gaussian is launched. The geometry of laser scribed grooves and the electrical performance of the cells are characterised. More homogenous ablation and material removal are achieved using top-hat hence the dopants from the isolation groove area are eliminated efficiently. The results from I-V characterisation confirm that more efficient isolation process and better isolation quality can be achieved using top-hat.


2019 ◽  
Vol 2019.13 (0) ◽  
pp. B15
Author(s):  
Ryoutarou MATSUDA ◽  
Keiji OGAWA ◽  
Takumi IMADA ◽  
Tadashi MAKIYAMA ◽  
Heisaburo NAKAGAWA

2019 ◽  
Vol 11 (15) ◽  
pp. 4079 ◽  
Author(s):  
Ana J. López ◽  
Alberto Ramil ◽  
José S. Pozo-Antonio ◽  
Teresa Rivas ◽  
Dolores Pereira

Conservation strategies to reduce the degradation of stone caused by the action of water are focusing on increasing the hydrophobicity of the surface by imitating existing solutions in nature (lotus leafs and others). These are mainly based on the existence of hierarchical roughness with micro- and nanoscale structures. In the case of marble, research has focused on protective coatings that sometimes are dangerous for the health and the environment, and with undesirable effects such as color changes or reduction of water vapor permeability of the stone. Laser texturing, however, is an environmentally friendly technique, because no chemicals or toxic waste are added and, moreover, it can process nearly all types of materials. It has been used to change the surface texture of metals and other materials on a micro or even nanometric scale, to meet a specific functional requirement, such as hydrophobicity. The objective of this work was to analyze the feasibility of this technique to provide hydrophobic properties to a marble surface without appreciable changes in its appearance. Therefore, an analysis of the irradiation parameters with ultra-short-pulse laser was performed. Preliminary results demonstrate the ability of this technique to provide hydrophobic character the marble (contact angles well above 90 ∘ ). Besides, the analysis of the treated surfaces in terms of roughness, color and gloss indicates that changes in the appearance of the surface are minimal when properly selecting the process parameters.


2021 ◽  
Vol 63 (12) ◽  
pp. 124006
Author(s):  
R A Simpson ◽  
D A Mariscal ◽  
J Kim ◽  
G G Scott ◽  
G J Williams ◽  
...  

Abstract Proton radiography using short-pulse laser drivers is an important tool in high-energy density (HED) science for dynamically diagnosing key characteristics in plasma interactions. Here we detail the first demonstration of target-normal sheath acceleration (TNSA)-based proton radiography the NIF-ARC laser system aided by the use of compound parabolic concentrators (CPCs). The multi-kJ energies available at the NIF-ARC laser allows for a high-brightness proton source for radiography and thus enabling a wide range of applications in HED science. In this demonstration, proton radiography of a physics package was performed and this work details the spectral properties of the TNSA proton probe as well as description of the resulting radiography quality.


2009 ◽  
Vol 131 (2) ◽  
Author(s):  
A. Shinkarenko ◽  
Y. Kligerman ◽  
I. Etsion

This paper presents a nonlinear theoretical model to study the effect of laser surface texturing on the tribological performance in soft elastohydrodynamic lubrication. Both geometrical and physical nonlinearities of the elastomer are considered by using a logarithmic strain and the Mooney–Rivlin constitutive law, respectively. The results of the present nonlinear model are compared with a previous linear one over a wide range of operating conditions. It is found that the simpler linear elasticity model predicts results that are only slightly different from these predicted by the more accurate nonlinear one. Hence, the linear elasticity model can be practically considered valid over the entire range of operating conditions.


10.2172/9636 ◽  
1999 ◽  
Author(s):  
P S Banks ◽  
M D Feit ◽  
A Komashko ◽  
M D Perry ◽  
A M Rubenchik ◽  
...  

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