JLA Vol:18 Iss:2 (Laser igniting synthesis of TiC powders with Al, Ti and C powders)
Authors:
Y. X. Li
J. D. Hu
S. Y. Liu
H. Y. Wang
Y. Yang
Z. X. Guo
The Key Lab of Automobile Materials, Ministry of Education, College of Materials Science and Engineering, Jilin University, No. 142 Renmin Street, Changchun 130025, People’s Republic of ChinaLaser ignited self-propagating high-temperature synthesis (LISHS) was used to fabricate TiC powders. The raw powders are Ti, Al, and C powders, respectively. A pulsed Nd-yttrium–aluminum–garnet laser was used to ignite reaction in argon atmosphere. The effects of Al content and laser average energy on density, phase composition, microstructure of the...
$25.00
JLA Vol:18 Iss:2 (Laser processing of polycrystalline diamond, tungsten carbide, and a related composite material)
Authors:
Paul M. Harrison
Matthew Henry
Michael Brownell
Powerlase Ltd., Imperial House, Link 10, Napier Way, Crawley, West Sussex RH10 9RA, United KingdomThere are numerous industrial uses of superhard materials such as polycrystalline diamond, natural diamond, and tungsten carbide. These include tooling for mechanical processing as well as robust substrates for microelectronics in extreme environment applications. Processing these materials has presented a perennial problem for engineers. In this article cutting and milling of these materials is investigated using high average power nanosecond pulsed diode pumped solid-state lasers. The results are investi...
$25.00
JLA Vol:18 Iss:2 (Marking of lines on clay brick pavers by vitrification with a Nd:YAG laser)
Authors:
J. W. Restrepo
J. M. Ferna´ndez-Pradas
M. A. Go´mez
P. Serra
J. L. Morenza
Universitat de Barcelona, Departament de Fi´sica Aplicada i Òptica, Marti´ i Franquès 1, E-08028 Barcelona, SpainLaser marking of architectural materials is nowadays an attractive technique for industrial and decorative applications. We report the clay brick pavers marking by vitrification with a continuous-wave Nd:YAG laser (λ=1.064 μm), at different output powers and scan speeds of the laser beam. The marked lines resulted in a dark green glassy phase. The width, depth, and cross-section area of ...
$25.00
JLA Vol:18 Iss:3 (A two-dimensional thermal finite element model of laser transmission welding for T joint)
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, CanadaRecent years have seen wider application of laser transmission welding (LTW) as a means for joining of plastic components. Advantages of LTW arise from it being a contact-free method for delivering precisely controlled energy to the surfaces of the welded components and from flexibility with regard to welding geometry afforded by the laser being under computer control. LTW involves a laser beam p...
$25.00
JLA Vol:18 Iss:3 (Controlled-fracture of prescored alumina ceramics using simultaneous CO<sub>2</sub> lasers)
Authors:
P. Brugan
G. Cai
R. Akarapu
A. E. Segall
The Pennsylvania State University, University Park, Pennsylvania 16802While brittle materials such as ceramics will clearly be at the forefront of improved energy efficiency, manufacturing problems related to shaping have proven to be troublesome. Fortunately, the usage of laser machining to shape structural ceramics is increasingly gaining acceptance as an alternative to traditional grinding and cutting methods. Despite the great promise of lasers for a variety of cutting and drilling procedures, premature fractures, poor surface quality, microscale damage, and prohibitively low cutting-speeds a...
$25.00
JLA Vol:18 Iss:3 (Femtosecond laser bulk micromachining of microfluid channels in poly(methylmethacrylate))
Authors:
Dave F. Farson
Hae Woon Choi
Department of Industrial, Welding and Systems Engineering, The Ohio State University, Columbus, Ohio 43221
Chunmeng Lu
L. James Lee
Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43221Internal channels in a polymer are widely used in biotechnology applications such as DNA stretching and in devices such as micrototal analysis systems and lab on a chip systems. For manufacturing prototype devices, femtosecond pulsed laser energy has been used to implement a convenient direct write bulk-machining process in glass. In this technique, the laser beam is focu...
$25.00
JLA Vol:18 Iss:3 (Femtosecond laser production of metal surfaces having unique surface structures that are broadband absorbers)
Authors:
Neha Singh
Dennis R. Alexander
John Schiffern
David Doerr
Center for Electro Optics and Electrical Engineering Department, University of Nebraska-Lincoln, 248 N WSEC, Lincoln, Nebraska 68588-0511Femtosecond laser induced modification of surface structure and the optical properties of metals are studied. A Ti:sapphire femtosecond laser is used for ablating bulk aluminum 2024 T3 alloy and highly pure neutron activation quality gold metal samples at different laser irradiation parameters. The ablation parameters are optimized for the two metals to form a low reflection surface in the wavelength range of 0.3–50 μm. “Blac...
$25.00
JLA Vol:18 Iss:3 (Hybrid laser beam welding—Classification, characteristics, and applications)
Authors:
A. Mahrle
University of Technology at Dresden, Institute for Surface Technology and Production Metrology, Postbox, D-01062 Dresden, Germany
E. Beyer
University of Technology at Dresden, Institute for Surface Technology and Production Metrology, Postbox, D-01062 Dresden, Germany and Fraunhofer Institute for Material and Beam Technology, Winterbergstr. 28, D-01277 Dresden, GermanyHybrid laser welding technologies can be defined as the combination of a high quality laser heat source with an additional secondary heat source. Based on such a definition, known hybrid techniques are classified by the type of the heat sources used as well as their arrangement r...
$25.00
JLA Vol:18 Iss:3 (In-line failure detection and diagnosis of excimer laser-based microvia fabrication using computational intelligence)
Authors:
Ronald Setia
Gary S. May
School of Electrical and Computer Engineering, Packaging Research Center, Georgia Institute of Technology, Atlanta, Georgia 30332-0250In this article, two computational intelligent methodologies for run-to-run, in-line excimer laser ablation process failure detection and diagnosis are compared. The techniques used are: (1) a combination of feed-forward neural networks and Dempster-Shafer theory; and (2) adaptive neurofuzzy networks. Both methodologies employ response data originating directly from the laser equipment and characterization of microvias formed by the ablation process, which serves as evidence of equipment malfunctions affec...
$25.00
JLA Vol:18 Iss:3 (Investigation of the effects of nonconventional beam geometries in laser surface treatment of ceramics: Experimental analysis)
Authors:
D. Triantafyllidis
Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M60 1QD, United Kingdom and Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 1QD, United Kingdom
L. Li
Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M60 1QD, United Kingdom
F. H. Stott
Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M60 1QD, United KingdomLaser surface treatment of ceramics by melting and re...
$25.00