JLA Vol:5 Iss:1 (Heat Flow in Laser Die Blank Welding)

Authors:
Y.‐S. Yang
C. R. Hsu
C. E. Albright
Y. Kuroda

Laser welded die blanks are finding increased usage in many industrial applications. This investigation was undertaken to establish a simplified means of calculating thermal cycles experienced in the fusion and heat affected zones on laser welds typically used in die blank welding. A planar solution domain perpendicular to the direction of travel was selected to simplify the finite element calculations. The resulting calculation technique provided reasonably accurate prediction of the thermal cycles measured by Moon and Metzbower, and the size of fusion zones and heat affected zones o...

JLA Vol:5 Iss:1 (LASER CUTTING OF STEELS: A physical and chemical analysis of the particles ejected during cutting. Part II)

Authors:
J. Powell
A. Ivarson
C. Magnusson

This paper is a continuation of work published in an earlier edition of this journal[1]. Both papers deal with the results of a detailed analysis of the particles ejected from the cut zone during laser cutting of mild and stainless steels. Reference 1 presented the thermochemical data and discussion generated by the experimental investigation. This paper concentrates on the physical characteristics and metallography of the particles. Analysis techniques used included: Scanning Electron Microscopy, optical microscopy, metallography and particle sizing. The results from this extensive analysis have enabled the authors...

JLA Vol:5 Iss:1 (Prediction Of Cavity Shape And Material Removal Rates Using A Two Dimensional Axisymmetric Heat Conduction Model For Fibrous Ceramic Insulation And Comparison With Experiments)

Authors:
Mingli He
P. J. Bishop
A. Minardi
University of Central Florida

High power lasers are used in industry as machining tools for many operations including drilling, cutting, welding, and etching. Because of its advantages over conventional machining such as tight tolerances, ability to machine hard materials without wearing of the machine tool, and ease of automation, an experimental and analytical study was undertaken to investigate the feasibility of the laser to cut a nearly pure fibrous ceramic used as insulation material on the Space Shuttle. An analytical model was developed for drilling using a spatially varying laser beam. The model was used to ...

JLA Vol:4 Iss:3 (Laser Safety in Health Care Facilities — Revision of ANSI Z136.3‐1988)

Authors:
Rocco V. Lobraico
Co‐chairman Z136.3 subcommittee

JLA Vol:4 Iss:3 (Where We Are Today: International Update)

Authors:
Jerry Glen
Union, Kentucky

JLA Vol:4 Iss:3 (Using the Proposed ANSI Z136.1‐1992 Standard)

Authors:
R. James Rockwell
Rockwell Laser Industries

JLA Vol:4 Iss:3 (Proposed Z136.1 Revision Nears ANSI Approval)

Authors:
Ami Kestenbaum
Secretary Z136 Accredited Standards Committee

JLA Vol:4 Iss:3 (ANSI Laser Safety Standard Historical Development)

Authors:
M. L. Wolbarsht
D. H. Sliney

JLA Vol:4 Iss:3 (Recommendations for Safe and Appropriate Use of Lasers in Dentistry in Face of Rising Concerns)

Authors:
Leo J. Miserendino
Elliot Abt
David Harris
Harvey Wigdor
The Chicago Dental Laser Institute

JLA Vol:5 Iss:1 (Determining the Spot Size and Gaussian Distribution Coefficient of Pulsed Laser Beams Using KAPTON Films)

Authors:
Z. Y. Wang
J. T. Liu
D. M. Hirak
D. C. Weckman
H. W. Kerr
Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 Canada

The laser beam spot size at the focal point of a pulsed laser is a critical parameter in laser materials processing, but accurate determination of the spot size is very difficult, particularly for high power pulsed lasers. In this study, effective methods were developed for such determination, by interpretation of measured hole diameters produced in Kapton film using pulsed laser beams with multimode or Gaussian‐like mode structures. Analysis of the hole‐makin...