JLA Vol:25 Iss:1 (Investigation on multi-track multi-layer epitaxial growth of columnar crystal in direct laser forming)

Authors:
XuanTuoi Do
State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, No. 28, Xianning West Road, Xi'an 710049, China and Le Quy Don University, No. 100, Hoang Quoc Viet Street, Hanoi 7EN-218, Vietnam

Dichen Li
Anfeng Zhang
Bin He
Haiyang Zhang
State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, No. 28, Xianning West Road, Xi'an 710049, China

Tatkhoa Doan
State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, No. 28, Xianning West Road, Xi'an 710049, China and Le Quy Don Technical Univers...

JLA Vol:25 Iss:1 (Review on laser drilling I. Fundamentals, modeling, and simulation)

Authors:
Wolfgang Schulz
Fraunhofer Institute for Laser Technology, ILT, Aachen, Germany and Nonlinear Dynamics of Laser Processing, RWTH Aachen University, 52074 Germany

Urs Eppelt
Nonlinear Dynamics of Laser Processing, RWTH Aachen University, 52074 Germany

Reinhart Poprawe
Fraunhofer Institute for Laser Technology, ILT, Aachen, Germany and Nonlinear Dynamics of Laser Processing, RWTH Aachen University, 52074 Germany

High peak power lasers have been used for years for ablating matter. The most relevant application of this process is laser marking. Marking meets the demands of applications although the quality of ablation has potential to b...

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 (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...

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:3 (Analysis of nanosecond laser ablation of aluminum with and without phase explosion in air and water)

Authors:
Yunfeng Cao
Xin Zhao
Yung C. Shin
Center for Laser-based Manufacturing, Purdue University, West Lafayette, Indiana 47907

Despite extensive research work, accurate prediction of the ablation behavior in the high energy nanosecond laser ablation process is still lacking, which may differ significantly depending on laser parameters, surrounding medium, and target material characteristics. In this paper, nanosecond laser ablation of aluminum in air and water is investigated through a self-contained hydrodynamic model under different laser fluences involving no phase explosion and phase explosion. The ablation depths and profiles are predicted and validat...

JLA Vol:25 Iss:3 (Evaluation of corneal and eye lens irradiance for optical aided viewing)

Authors:
Enrico Galbiati
GEST Labs, Via Kennedy, 20871 Vimercate, Italy

The use of a magnifying lens with a highly divergent laser beam may cause a big increase of the irradiance on the cornea and the eye lens. This study provides the analysis of several cases where the use of a lens lead to a corneal irradiance significantly higher than the naked-eye viewing. The examples analyzed in this study allow determining the factors that represent the increase of the corneal irradiance caused by the use of the lens. The results indicate that these factors of irradiance increase may be close to 100.

JLA Vol:25 Iss:3 (Laser direct joining of carbon fiber reinforced plastic to aluminum alloy)

Authors:
Kwang-Woon Jung
Yousuke Kawahito
Makoto Takahashi
Seiji Katayama
Joining and Welding Research Institute (JWRI), Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan

Laser direct joining of carbon fiber reinforced plastic (CFRP) to aluminum alloy was performed using a high quality continuous wave diode laser with a line-shaped beam. The tensile shear test results demonstrated that a strong lap joint with about 3000 N could be produced between CFRP (of 3 mm thickness and 20 mm width) and aluminum alloy (of 2 mm thickness and 30 mm width). The joints fractured along the joint interface or in the melted zone of CFRP. It was obser...

JLA Vol:25 Iss:3 (Laser processing of nickel–aluminum bronze for improved surface corrosion properties)

Authors:
R. Cottam
T. Barry
Industrial Laser Applications Laboratory, IRIS, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Victoria 3122, Australia and Defence Materials Technology Centre, Victoria 3122, Australia

D. McDonald
Department of Mechanical Engineering, The University of Melbourne, Victoria 3010, Australia and Defence Materials Technology Centre, Victoria 3122, Australia

H. Li
Faculty of Engineering, University of Wollongong, New South Wales 2522, Australia and Defence Materials Technology Centre, Victoria 3122, Australia

D. Edwards
A. Majumdar
Defence Science and T...

JLA Vol:25 Iss:3 (Laser-assisted plasma arc welding of stainless steel)

Authors:
Achim Mahrle
Institut fu¨r Fertigungstechnik IF, Technische Universita¨t Dresden, 01062 Dresden, Germany and Fraunhofer IWS Dresden, Winterbergstrasse 28, 01277 Dresden, Germany

Sascha Rose
Michael Schnick
Institut fu¨r Fertigungstechnik IF, Technische Universita¨t Dresden, 01062 Dresden, Germany

Eckhard Beyer
Institut fu¨r Fertigungstechnik IF, Technische Universita¨t Dresden, 01062 Dresden, Germany and Fraunhofer IWS Dresden, Winterbergstrasse 28, 01277 Dresden, Germany

Uwe Fu¨ssel
Institut fu¨r Fertigungstechnik IF, Technische Universita¨t Dresden, 01062 Dresden, Germany