Temporal Pulse Tailoring in Ultrafast Laser Manufacturing Technologies

Author(s):  
Razvan Stoian ◽  
Matthias Wollenhaupt ◽  
Thomas Baumert ◽  
Ingolf V. Hertel
Author(s):  
Chao Ma ◽  
Jingzhou Zhao ◽  
Chezheng Cao ◽  
Ting-Chiang Lin ◽  
Xiaochun Li

It is of great scientific and technical interests to conduct fundamental studies on the laser interactions with nanoparticles-reinforced metals. This part of the study presents the effects of nanoparticles on surface tension and viscosity, thus the heat transfer and fluid flow, and eventually the laser melting process. In order to determine the surface tension and viscosity of nanoparticles-reinforced metals, an innovative measurement system was developed based on the characteristics of oscillating metal melt drops after laser melting. The surface tensions of Ni/Al2O3 (4.4 vol. %) and Ni/SiC (3.6 vol. %) at ∼1500 °C were 1.39 ± 0.03 N/m and 1.57 ± 0.06 N/m, respectively, slightly lower than that of pure Ni, 1.68 ± 0.04 N/m. The viscosities of these Ni/Al2O3 and Ni/SiC MMNCs at ∼1500 °C were 13.3 ± 0.8 mPa·s and 17.3 ± 3.1 mPa·s, respectively, significantly higher than that of pure Ni, 4.8 ± 0.3 mPa·s. To understand the influences of the nanoparticles-modified thermophysical properties on laser melting, an analytical model was used to theoretically predict the melt pool flows using the newly measured material properties from both Part I and Part II. The theoretical analysis indicated that the thermocapillary flows were tremendously suppressed due to the significantly increased viscosity after the addition of nanoparticles. To test the hypothesis that laser polishing could significantly benefit from this new phenomenon, systematic laser polishing experiments at various laser pulse energies were conducted on Ni/Al2O3 (4.4 vol. %) and pure Ni for comparison. The surface roughness of the Ni/Al2O3 was reduced from 323 nm to 72 nm with optimized laser polishing parameters while that of pure Ni only from 254 nm to 107 nm. The normalized surface roughness reduced by nearly a factor of two with the help of nanoparticles, validating the feasibility to tune thermophysical properties and thus control laser-processing outcomes by nanoparticles. It is expected that the nanoparticle approach can be applied to many laser manufacturing technologies to improve the process capability and broaden the application space.


2003 ◽  
Vol 83 (7) ◽  
pp. 1474-1476 ◽  
Author(s):  
M. Spyridaki ◽  
E. Koudoumas ◽  
P. Tzanetakis ◽  
C. Fotakis ◽  
R. Stoian ◽  
...  

Author(s):  
Panos Stavropoulos ◽  
Angelos Koutsomichalis ◽  
Nikos Vaxevanidis

In this chapter the latest developments in Laser manufacturing technologies and processes, used in the aerospace industry, are discussed. Current developments in the aerospace industry are characterised by the reduction of manufacturing and exploitation costs. Thus, the need for implementation of advanced manufacturing technologies and processes in the aeronautic industry, offering cost effective products with improved life cycle, is becoming more and more imperative. Lasers can be used in many industrial machining processes for a variety of materials including metals, ceramics, glass, plastics, and composites. Laser beams, used as machining tools, are not accompanied by problems such as tool wear, tool breakage, chatter, machine deflection and mechanically induced material damage, phenomena that are usually associated with traditional machining processes. The effectiveness of Lasers depends on the thermal nature of the machining process. Nevertheless, difficulties arise due to the difference in the thermal properties of the various components.


2010 ◽  
Vol 18 (11) ◽  
pp. 11159 ◽  
Author(s):  
M. Guillermin ◽  
A. Klini ◽  
J. P. Colombier ◽  
F. Garrelie ◽  
D. Gray ◽  
...  

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Felix Sima ◽  
Koji Sugioka

Abstract In the last decades, research and development of microfluidics have made extraordinary progress, since they have revolutionized the biological and chemical fields as a backbone of lab-on-a-chip systems. Further advancement pushes to miniaturize the architectures to nanoscale in terms of both the sizes and the fluid dynamics for some specific applications including investigation of biological sub-cellular aspects and chemical analysis with much improved detection limits. In particular, nano-scale channels offer new opportunities for tests at single cell or even molecular levels. Thus, nanofluidics, which is a microfluidic system involving channels with nanometer dimensions typically smaller than several hundred nm, has been proposed as an ideal platform for investigating fundamental molecular events at the cell-extracellular milieu interface, biological sensing, and more recently for studying cancer cell migration in a space much narrower than the cell size. In addition, nanofluidics can be used for sample manipulation in analytical chemistry, such as sample injections, separation, purifications or for quantitative and qualitative determinations. Among the nanofabrication technologies, ultrafast laser manufacturing is a promising tool for fabrication of nanofluidics due to its flexibility, versatility, high fabrication resolution and three dimensional (3D) fabrication capability. In this paper, we review the technological advancements of nanofluidic systems, with emphasis on fabrication methods, in particular ultrafast laser manufacturing. We present the challenges for issues concerning channel sizes and fluid dynamics, and introduce the applications in physics, biology, chemistry and engineering with future prospects.


2014 ◽  
Vol 223 ◽  
pp. 325-332 ◽  
Author(s):  
Jacek Reiner ◽  
Wojciech Cieszyński ◽  
Maksymilian Sidorowicz ◽  
Marcin Wiercioch ◽  
Edward Chlebus

Manufacturing technologies using laser radiation energy are gaining increasingly new applications. It results from their numerous advantages, most of all, from the selectiveness of a laser beam within the spatial and temporal domain. Although the laser beam is a very precise tool, it restricts the tolerances of component preparation. If such increased requirements drive previous processes, it will result in the increase of manufacturing costs of these parts. Hence, solutions are sought in the mechatronics paradigm, which corrects mechanical imperfections by means of electronics and software. Examples of the above solutions are follow-up and adaptive control systems. The paper presents examples of developed and implemented control systems of laser manufacturing processes with machine vision feedback. They include remote cutting with CAM-MV and laser cladding with a thermal or geometric closed-loop.


2003 ◽  
Author(s):  
Razvan Stoian ◽  
Mark Boyle ◽  
Andreas Thoss ◽  
Arkadi Rosenfeld ◽  
Georg Korn ◽  
...  

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