JLA Vol:3 Iss:1 (Laser Welding Copper and Copper Alloys)

Authors:
Kaoru Hashimoto
Takehiko Sato
Koichi Niwa
Fujitsu Laboratories Ltd., 10‐1, Morinosato‐Wakamiya, Atsugi 243‐01, Japan

We have developed a laser hermetic sealing technique that combines nickel plating with laser welding for copper and copper alloy bellows for general purpose large‐scale computers. Laser welding of copper has been difficult because of copper's high thermal conductivity and reflectivity. However, laser welding nickel‐plated copper results in deep penetration. To avoid corrosion induced at the dissimilar metal contact between nickel and copper, the nickel‐plated copper was heat‐treated bef...

JLA Vol:14 Iss:3 (Appropriate regimes of laser drilling models containing melt eject mechanisms)

Authors:
S. S. Kudesia
Department of Physics, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, United Kingdom

P. Solana
Departamento de Matema´tica Aplicada, Universidad Polite´cnica de Madrid, Spain

W. S. O. Rodden
D. P. Hand
J. D. C. Jones
Department of Physics, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, United Kingdom

The significance of melt ejection during various drilling regimes of laser drilling is investigated. The predictions of two analytical models of the drilling process, with and without the melt ejection mechanism, are compared with experimental measurements made using a ...

JLA Vol:18 Iss:3 (Multiscale modeling of solidification during laser cladding process)

Authors:
Y. Cao
J. Choi
Department of Mechanical and Aerospace Engineering, University of Missouri-Rolla, Rolla, Missouri 65409-1060

Laser cladding is an additive manufacturing process in which a laser generates a melt pool on the substrate material while a second material in a powder or wire form is injected into that melt pool. Among all laser manufacturing processes, laser cladding offers the most extensive variety of possibilities to alter a component at its surface. Despite immense potential and advancements, the process model of microstructure evolution and its coupling with macro parameters of the laser cladding process has not been fully developed. To address this...

JLA Vol:24 Iss:3 (Laser cladding for railway repair and preventative maintenance)

Authors:
Adam Clare
Olusola Oyelola
Janet Folkes
Peter Farayibi
Innovative Manufacturing Processes Group, Manufacturing Division, Faculty of Engineering, The University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom

Rolling contact fatigue, amongst other mechanisms of wear, between railway track and train wheel ensures that periodic replacement of worn track and other key components such as switches must be undertaken. The cost associated with repairing/replacing track is significant. This places a financial burden upon the rail network provider, creates a significant carbon footprint associated with remanufacture of track, an...

JLA Vol:6 Iss:4 (Erratum: Excimer laser processing of Ti–6Al–4V)

Authors:
J. A. Folkes
K. Shibata
Nissan Motor Co. Ltd, Materials Research Laboratory, Central Engineering Laboratories, 1, Nasushima‐cho, Yokosuka 237, Japan

JLA Vol:17 Iss:1 (Microstructural characterization of dissimilar laser weld between austenitic and ferritic stainless steels)

Authors:
Rakesh Kaul
P. Ganesh
A. K. Nath
Industrial CO2 Laser Section, Centre for Advanced Technology, P. O. CAT, Indore 452 013, India

The present work involved microstructural characterization of thin sheet dissimilar laser welds between type 304 austenitic stainless steel and stabilized 17% Cr ferritic stainless steel and their comparison with welds produced by autogenous gas tungsten arc welding (GTAW). Low heat input of laser welding (LW) effectively reduced the size of fusion zone (FZ) and heat affected zone (HAZ). LW with focused laser beam (LB), preferentially displaced towards austenitic stainless steel (ASS), produced FZ with uniform and highly ref...

JLA Vol:21 Iss:3 (Infrared observations and finite element modeling of a laser transmission welding process)

Authors:
L. S. Mayboudi
A. M. Birk
G. Zak
Mechanical and Materials Engineering, Queen’s University, Kingston, Ontario K7L 3N6, Canada

P. J. Bates
Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario K7K 7B4, Canada

Laser transmission welding (LTW), a technique to join thermoplastic components, involves a laser beam passing through a laser-transmitting part and then being absorbed by the laser-absorbing part at the weld interface. To form a strong bond, it is important that the weld interface be exposed to sufficient heat to melt the polymer without degrading it. A lap-joint geometry was investigated and the...

JLA Vol:8 Iss:6 (Laser surface alloying of magnesium base alloys)

Authors:
R. Galun
A. Weisheit
B. L. Mordike
Institut fu¨r Werkstoffkunde und Werkstofftechnik, Technische Universita¨t Clausthal, Agricolastraße 6, D‐38678 Clausthal‐Zellerfeld, Germany

The feasibility of the laser surface alloying of magnesium base alloys with aluminum, copper, nickel and silicon has been shown in this work. By laser alloying with these elements, using a 5 kW CO₂‐laser, the hardness of several magnesium base alloys can be increased to values above 250 HV_0.1. Melted depths from 700–1200 μm and alloying contents from 15–55 at % were achieved. The wear resistance of ...

JLA Vol:1 Iss:4 (Optical Methods in Flow Visualization)

Authors:
Wen‐Jei Yang
Yi Chen
Department of Mechanical Engineering and Applied Mechanics, The University of Michigan, Ann Arbor, Michigan 48109

Optical techniques for flow visualization are presented, including light‐sheet flow visualization, shadowgraphy, schlieren method, interferometry, holography, speckle photography, laser‐induced fluorescence and thermography. The principles of these methods are briefly described and the examples of their applications to flow visualization are given.

JLA Vol:1 Iss:1 (Laser Application in Otolaryngology — Head and Neck Surgery)

Authors:
Michael Barat
Robert H. Ossoff
Vanderbilt University Medical Center, Department of Otolaryngology, Nashville, Tennessee

Since the discovery of the laser in 1959, a wide variety of lasers have been developed with numerous clinical applications in medicine and surgery. Lasers have had a great impact on the surgical approach to both benign and malignant diseases in Otolaryngology‐Head and Neck Surgery, and have enabled the otolaryngologist to manage diseases in the aerodigestive system primarily through an endoscopic approach. We will summarize the physical properties of the currently used lasers in otolaryngology, as well as their clinical applications.