• JLA Vol:15 Iss:1 (Melting characteristics of metals by combined laser beams with different wavelengths)

    Jong Hyun Moon
    Graduate School of Osaka University, Suitasi, Osaka 565-0871, Japan

    Masami Mizutani
    Seiji Katayama
    Akira Matsunawa
    Joining and Welding Research Institute, Osaka University 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan

    Infrared CO2 and yttritium–aluminum–garnet (YAG) lasers have great difficulty in melting metals such as pure aluminum and copper possessing high reflectivity and high thermal and electrical conductivity. On the other hand, the laser absorptance of such metals generally increases with the decrease in the wavelength, and thus the application of laser with higher power and shorte...


  • JLA Vol:15 Iss:1 (Microstructure and corrosion behavior of high power diode laser deposited Inconel 625 coatings)

    J. Tuominen
    Laser Application Laboratory, Tampere University of Technology, FIN-33101 Tampere, Finland

    P. Vuoristo
    T. Ma¨ntyla¨
    Institute of Materials Science, Tampere University of Technology, FIN-33101 Tampere, Finland

    J. Latokartano
    J. Vihinen
    Laser Application Laboratory, Tampere University of Technology, FIN-33101 Tampere, Finland

    P. H. Andersson
    Institute of Production Engineering, Tampere University of Technology, FIN-33101 Tampere, Finland

    A series of experiments were performed to investigate the one-step laser cladding of Inconel 625 powder, injected off-axially onto m...


  • JLA Vol:15 Iss:1 (Specific energy for pulsed laser rock drilling)

    Z. Xu
    C. B. Reed
    G. Konercki
    Technology Development Division, Argonne National Laboratory, Argonne, Illinois 60540

    R. A. Parker
    Parker Geoscience Consulting, LLC, Arvada, Colorado 80403

    B. C. Gahan
    Gas Technology Institute, Des Plains, Illinois 60018

    S. Batarseh
    R. M. Graves
    Department of Petroleum Engineering, Colorado School of Mines, Golden, Colorado 80401

    H. Figueroa
    Petroleos de Venezuela INTEVEP, S.A., Caracas 1070A, Venezuela

    N. Skinner
    Halliburton Energy Service, Carrollton, Texas 75006

    Application of advanced high power ...


  • JLA Vol:15 Iss:2 (Antigalling and low friction properties of a laser processed Co-based material)

    D. H. E. Persson
    Duroc AB, Umeå, Sweden

    S. Jacobson
    S. Hogmark
    The Tribomaterials Group at Ångstro¨m Laboratory, Uppsala University, Sweden

    The antigalling and low friction properties of a CO2-laser processed Co-based material (Stellite 21) was investigated under high-load sliding conditions. Dry sliding tests were carried out at both room temperature and at 250 °C. The tests were performed by sliding two identical specimens against each other in a dedicated test. A low and stable friction coefficient at a level of about 0.20, and relatively independent on load and sliding speed, was obtained after a short runn...


  • JLA Vol:15 Iss:2 (Automatic detection of lack of fusion defects in CO<sub>2</sub> laser gear welding)

    A. Ghasempoor
    Department of Mechanical, Aerospace, and Industrial Engineering, Ryerson University, Toronto, Ontario M5B 2K3, Canada

    P. Wild
    M. Auger
    Department of Mechanical Engineering, Queen’s University, Kingston, Ontario K7K 3N6, Canada

    R. Mueller
    Powerlasers Ltd., Advanced Technologies Centre, Kitchener, Ontario N2G 2Y5, Canada

    Laser welding is becoming increasingly important in the automotive industry and quality of the weld is critical for a successful application. In many cases the increase in welding speed provided by laser welding has resulted in the need for an automated, on-line weld monitoring system....


  • JLA Vol:15 Iss:2 (Characteristics of high-power diode&ndash;laser welds for industrial assembly)

    C. A. Walsh
    H. K. D. H. Bhadeshia
    Department of Materials Science and Metallurgy, University of Cambridge, United Kingdom

    A. Lau
    B. Matthias
    R. Oesterlein
    ABB Corporation Research, Ladenburg, Germany

    J. Drechsel
    Laserinstitut Mittelsachsen e.V., Mittweida, Germany

    Recent progress in available beam power and beam quality has meant that high power diode lasers may soon become prime tools for welding in many assembly applications in industrial production. Their compact size and low weight makes them particularly suitable for use in conjunction with robotic control. The advantages of laser welding ...


  • JLA Vol:15 Iss:2 (Copper vapor laser micromachining of 304 stainless steel)

    M. El-Bandrawy
    K. Nagarathnam
    Mool C. Gupta
    Applied Research Center, College of Engineering and Technology, Old Dominion University, Newport News, Virginia 23606

    C. Hamann
    J. Horsting
    Siemens Automotive, Newport News, Virginia 23606

    A copper vapor laser (CVL) of 511/578 nm wavelength, 25 ns pulse width, and 10 kHz repetition rate combined with a computer controlled galvo head was used for laser micromachining of 304 stainless steel. The objective of this study was to develop the CVL micromachining process and its optimization. We observed a significant improvement in micromachining quality with a spatially filtered ...


  • JLA Vol:15 Iss:2 (Corrosion resistance of laser-fabricated metal&ndash;matrix composite layer on stainless steel 316L)

    K. H. Lo
    Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China

    C. T. Kwok
    Department of Electromechanical Engineering, Faculty of Science and Technology, University of Macau, Taipei, Macau, China

    F. T. Cheng
    Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China

    H. C. Man
    Department of Manufacturing Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China

    Laser fabrication of ceramic-reinforced metal–matrix composite (MMC) layer on stainless steel 316L was achieved by a two-st...


  • JLA Vol:15 Iss:2 (Critical parameters of light emitting diodes and their implications on the optical radiation safety limits according to IEC 60825-1 +Amendment 2)

    W. Horak
    R. Neuhaus
    Siemens AG, 81730 Munich, Germany

    Radiation power and image size of the source on the viewer's retina (apparent source) determines the hazard for the eye. Following IEC 60825-1, the effective emission limits are dependent on the tabulated accessible emission limits and the assigned measurement conditions—both depending on the source size. In the case of a light emitting diode (LED), this emitting area is not only determined by the chip size but also by the housing—due to built-in lenses, reflectors, and scattering materials. Also the virtual source position will be distorted by the integrated lenses. Since the measurement distance ...


  • JLA Vol:15 Iss:2 (Laser forming of thin foil by a newly developed sample holding method)

    Shunro Yoshioka
    Toshiyuki Miyazaki
    Tadashi Misu
    Ryugo Oba
    Masatoshi Saito
    Chiba Institute of Technology, Tsudanuma, Narashino-shi, Chiba 275-0016, Japan

    A sample holding method is newly developed for laser forming, in which the target material is held between two transparent plates. During laser beam scanning on the target, the target foil is kept flat. After the scanning is finished, the foil is detached from the holder; the foil bends toward the beam scanned surface. Experiments are carried out with a Nd:yttrium–aluminum–garnet laser beam for a spot size of 25μm and for a traverse speed of 10 mm/s. A bending...



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