Optimized energy coupling at ultrafast laser-irradiated metal surfaces by tailoring intensity envelopes: Consequences for material removal from Al samples

2006 ◽  
Vol 74 (22) ◽  
Author(s):  
J. P. Colombier ◽  
P. Combis ◽  
A. Rosenfeld ◽  
I. V. Hertel ◽  
E. Audouard ◽  
...  
2011 ◽  
Vol 1319 ◽  
Author(s):  
Michael J. Abere ◽  
Ryan D. Murphy ◽  
Bianca Jackson ◽  
Gerard Mourou ◽  
Michel Menu ◽  
...  

ABSTRACTAn ultrafast laser irradiation method for the removal of corrosion from Daguerreotypes without detrimentally affecting image quality has been developed. Corrosion products such as silver oxide and silver sulfide may be removed by chemical cleaning but these reactions are hard to control and are often damaging to the underlying silver, ruining the image. The Ti:Sapphire 150 fs laser pulses used in this study are focused to a beam diameter of 60 μm and are normally incident to the Daguerreotype. It was found that the corrosion layer has a lower material removal threshold than silver allowing for removal of corrosion with minimal removal of vital information contained in the silver substrate.


2020 ◽  
Vol 108 (1-2) ◽  
pp. 413-426 ◽  
Author(s):  
Panagiotis Stavropoulos ◽  
Alexios Papacharalampopoulos ◽  
Lydia Athanasopoulou

2003 ◽  
Vol 780 ◽  
Author(s):  
R. Stoian ◽  
S. Winkler ◽  
M. Hildebrand ◽  
M. Boyle ◽  
A. Thoss ◽  
...  

The possibility of phase manipulation and temporal tailoring of ultrashort laser pulses enables new opportunities for optimal processing of materials. Phase-manipulated ultrafast laser pulses allow adapting the laser energy delivery rate to the material properties for optimal processing laying the groundwork for adaptive optimization in materials structuring. Different materials respond with specific reaction pathways to the sudden energy input depending on the efficiency of electron generation and on the ability to release the energy into the lattice. The sequential energy delivery with judiciously chosen pulse trains may induce softening of the material during the initial steps of excitation and change the energy coupling for the subsequent steps. We show that this can result in lower stress, cleaner structures, and allow for a materialdependent optimization process.


2000 ◽  
Author(s):  
J. Sun ◽  
J. P. Longtin ◽  
P. M. Norris

Abstract Silica aerogels are unique nanostructured materials that possess many distinctive qualities, including extremely low densities and thermal conductivities, very high surface-area-to-volume ratios, and large strength-to-weight ratios. Aerogels, however, are very brittle, and are not readily shaped using traditional machining operations. Ultrafast laser processing may provide an alternative for precision shaping and machining of these materials. This paper discusses investigations of ultrafast laser machining of aerogels for material removal and micromachining. The advantages of ultrafast laser processing include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition. In this work, an amplified femtosecond Ti:sapphire laser system is used to investigate the breakdown threshold, material removal rate, and specific issues associated with laser processing of aerogels, as well as recommendations for further investigations for these unique materials.


1992 ◽  
Vol 114 (4) ◽  
pp. 421-426 ◽  
Author(s):  
D. E. Kim ◽  
N. P. Suh

A chemical etching method is investigated as a possible approach to smoothing metal surfaces automatically. In a chemical etching process metal is removed due to chemical reaction and the dissolved species are transported away from the surface mainly by diffusion. Controlled dynamics introduced to the etchant motion provide the conditions necessary to perform preferential material removal such that an irregular surface is smoothed. A simplified model for the smoothing process based on fundamental mass transfer understandings is presented. Experimental results of smoothing electric discharge machined 440 stainless steel specimens are also presented. This work is motivated by the need to develop a cost effective way to manufacture molds during secondary processing.


2019 ◽  
Vol 3 (1) ◽  
pp. 14 ◽  
Author(s):  
Krystian Wlodarczyk ◽  
Amiel Lopes ◽  
Paul Blair ◽  
M. Mercedes Maroto-Valer ◽  
Duncan P. Hand

We provide experimental evidence that the laser beam scanning strategy has a significant influence on material removal rate in the ultrafast laser machining of glass. A comparative study of two laser beam scanning methods, (i) bidirectional sequential scanning method (SM) and (ii) bidirectional interlaced scanning method (IM), is presented for micromachining 1.1-mm-thick borosilicate glass plates (Borofloat® 33). Material removal rate and surface roughness are measured for a range of pulse energies, overlaps, and repetition frequencies. With a pulse overlap of ≤90%, IM can provide double the ablation depth and double the removal rate in comparison to SM, whilst maintaining very similar surface roughness. In both cases, the root-mean-square (RMS) surface roughness (Sq) was in the range of 1 μm to 2.5 μm. For a 95% pulse overlap, the difference was more pronounced, with IM providing up to four times the ablation depth of SM; however, this is at the cost of a significant increase in surface roughness (Sq values >5 μm). The increased ablation depths and removal rates with IM are attributed to a layer-by-layer material removal process, providing more efficient ejection of glass particles and, hence, reduced shielding of the machined area. IM also has smaller local angles of incidence of the laser beam that potentially can lead to a better coupling efficiency of the laser beam with the material.


Sign in / Sign up

Export Citation Format

Share Document