JLA Vol:24 Iss:5 (Laser cladding using scanning optics)

Authors:
I. J. Pekkarinen
V. Kujanpa¨a¨
A. Salminen
Laboratory of Laser Processing, Department of Mechanical Engineering, Lappeenranta University of Technology, Tuotantokatu 2, 53850 Lappeenranta, Finland

Laser cladding using scanning optics is a relatively little studied matter. Scanning optics makes the adjustment of laser beam interaction zone numerically possible and it is, therefore, a more flexible optical tool than the conventional static optics. A series of cladding test were conducted using a 5 kW fiber laser and an oscillating linear scanner with dynamic powder feeding to determine the process characteristics and their possibilities and limi...

JLA Vol:24 Iss:5 (Technical safety measures for the safe use of hand-held laser processing devices)

Authors:
Thomas Puester
Juergen Walter
Michael Hustedt
Volker Wesling
Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover, Germany

From an occupational safety point of view, the market launch of hand-held laser processing devices (HLDs) should be closely connected to machine safety qualification. In order to meet demands concerning a safe design of HLDs, research was performed to both develop and evaluate safety concepts for HLDs and to qualify technical measures for HLD laser safety. The work focused on the risk of injury especially for the skin arising from laser beam hazards by continuous-wave high-power laser systems typically use...

JLA Vol:24 Iss:5 (Flexible and efficient laser remote welding of ultra-thin metal foils)

Authors:
Andreas Patschger
Jens Bliedtner
University of Applied Science Jena, Carl-Zeiss-Promenade 2, Jena 07745, Germany

Matthias Hild
JENOPTIK Automatisierungstechnik GmbH, Konrad-Zuse-Straße 6, Jena 07745, Germany

Jean Pierre Bergmann
University of Technology Ilmenau, Neuhaus 1, Ilmenau 98693, Germany

This paper discusses investigations regarding flexible and efficient strategies of laser remote welding of ultra-thin metal foils (≤50 μm) which are applied in the fields of electronics, packaging, and construction. A single-mode fiber laser was used, equipped with a scanner head and diverse objectives. Thus...

JLA Vol:24 Iss:5 (A comparative study of cut front profiles and absorptivity behavior for disk and CO₂ laser beam inert gas fusion cutting)

Authors:
Leonardo Daniele Scintilla
Luigi Tricarico
Dipartimento di Meccanica, Matematica e Management (DMMM), Politecnico di Bari, Viale Japigia, 182–70126 Bari, Italy

Achim Mahrle
Institute of Manufacturing Technology, Technische Universita¨t Dresden, 01062 Dresden, Germany and Fraunhofer IWS Dresden, Winterbergstraße 28, 01277 Dresden, Germany

Andreas Wetzig
Fraunhofer IWS Dresden, Winterbergstraße 28, 01277 Dresden, Germany

Eckhard Beyer
Institute of Manufacturing Technology, Technische Universita¨t Dresden, 01062 Dresden, Germany and Fraunhofer IWS Dresden, Winterbergstraße 28, 01277 Dres...

JLA Vol:24 Iss:5 (Laser metal deposition of Inconel 625: Microstructure and mechanical properties)

Authors:
Marleen Rombouts
Gert Maes
Myrjam Mertens
Willy Hendrix
VITO, Vlaamse Instelling voor Technologisch Onderzoek, Department of Materials Technology, Boeretang 200, 2400 Mol, Belgium

Laser metal deposition (LMD) is used in industry to coat, additive manufacture, and/or repair high value metal components through deposition and laser induced melting of powder delivered in a gas stream. This study relates to the production of three-dimensional Inconel 625 components by LMD. After LMD, a dense cellular – dendritic structure containing carbides of the type MC, M₂₃C₆, and M₆C has been detected by x-ray diffr...

JLA Vol:25 Iss:1 (Spatial analysis of the back reflected laser light during CO₂-laser cutting of metal sheets)

Authors:
David Schindhelm
Graduate School of Excellence Advanced Manufacturing Engineering in Stuttgart (GSaME), Universita¨t Stuttgart, D-70569 Stuttgart, Germany and Institut fu¨r Strahlwerkzeuge (IFSW), Universita¨t Stuttgart, Pfaffenwaldring 43, D-70569 Stuttgart, Germany

Rudolf Weber
Thomas Graf
Institut fu¨r Strahlwerkzeuge (IFSW), Universita¨t Stuttgart, Pfaffenwaldring 43, D-70569 Stuttgart, Germany

During laser material processing such as laser welding or cutting, it is known that the whole laser power is not only absorbed in or transmitted through the interaction zone, but a significant percentage is also reflected back ...

JLA Vol:25 Iss:1 (Wettability modification of electrospun poly(ε-caprolactone) fiber by femtosecond laser irradiation)

Authors:
Lingna He
Dave F. Farson
Laboratory for Multiscale Processing and Characterization, The Ohio State University, 1248 Arthur E Adams Drive, Columbus, Ohio 43221 and Department of Materials Science and Engineering, The Ohio State University, 477 Watts Hall, 2041 College Road, Columbus, Ohio 43210

Jian Chen
Materials Science and Technology Division, Oak Ridge National Laboratory, One Bethel Road, P.O. Box 2008, MS-6095, Oak Ridge, Tennessee 37831-6095

John J. Lannutti
Department of Materials Science and Engineering, The Ohio State University, 477 Watts Hall, 2041 College Road, Columbus, Ohio 43210

Stan I. Rokhlin
Labora...

JLA Vol:25 Iss:1 (Fatigue crack propagation in laser alloyed ductile cast iron surface)

Authors:
Zheng-yang Li
Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China and Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, People's Republic of China

Hai-yan Zhao
Yu Gu
Min-lin Zhong
Bin Zhang
Hong-jun Zhang
Wen-jin Liu
Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, People's Republic of China

Zhi-yuan Ren
Ming-jiang Yang

JLA Vol:25 Iss:1 (Implementation of a novel scan localization system for wireless sensor networks)

Authors:
K. Sun
W. Huang
Sachula Meng
Y. Xiao
M. T. Wang
Z. Xiao
Inner Mongolia University, Hohhot 010021, China

A novel localization scheme called laser beam scan localization by combining grid and light (laser) with mobile localization policy for wireless sensor networks is designed. The scheme utilizes a moving location assistant (LA) with a laser beam, through which the deployed area is scanned. The LA sends identities to unknown nodes to obtain the locations of sensor nodes. High localization accuracy can be achieved without the aid of expensive hardware on the sensor nodes, as required by other localization systems...

JLA Vol:25 Iss:1 (Theoretical analysis of multiple-pulse thermal damage thresholds of the retina)

Authors:
C. D. Clark
TASC Inc., 4141 Petroleum Road, Suite 4007 Fort Sam Houston, Texas 78234

W. J. Marshall
Laser Safety Specialties, Wilmington, Delaware 19810

R. J. Thomas
Air Force Research Laboratory, 711 HPW/RHDO, 4141 Petroleum Road, Fort Sam Houston, Texas 78234

In this paper, we present a theoretical analysis of multiple-pulse thermal damage thresholds based on the Arrhenius integral damage model. We consider the dependence of thresholds on both the number of pulses and the pulse spacing and show that the trends can be understood by considering the thermal relaxation time. The biological data that exists in the multiple-pulse therma...