Modeling and design of energy concentrating laser weld joints

Milewski, J O; Sklar, E

Title: Modeling and design of energy concentrating laser weld joints

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Abstract

The application of lasers for welding and joining has increased steadily over the past decade with the advent of high powered industrial laser systems. Attributes such as high energy density and precise focusing allow high speed processing of precision assemblies. Other characteristics of the process such as poor coupling of energy due to highly reflective materials and instabilities associated with deep penetration keyhole mode welding remain as process limitations and challenges to be overcome. Reflective loss of laser energy impinging on metal surfaces can in some cases exceed ninety five percent, thus making the process extremely inefficient. Enhanced coupling of the laser beam can occur when high energy densities approach the vaporization point of the materials and form a keyhole feature which can trap laser energy and enhance melting and process efficiency. The extreme temperature, pressure and fluid flow dynamics of the keyhole make control of the process difficult in this melting regime. The authors design and model weld joints which through reflective propagation and concentration of the laser beam energy significantly enhance the melting process and weld morphology. A three dimensional computer based geometric optical model is used to describe the key laser parameters and joint geometry. Ray tracingmore »« less

Authors:

Milewski, J O ^[1]; Sklar, E ^[2]

Los Alamos National Lab., NM (United States)
OptiCad Corp., Santa Fe, NM (United States)

Publication Date:: Tue Apr 01 00:00:00 EST 1997

Research Org.:: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:: USDOE, Washington, DC (United States)

OSTI Identifier:: 461246

Report Number(s):: LA-UR-97-384; CONF-970369-1
ON: DE97004764; TRN: 97:002628

DOE Contract Number:: W-7405-ENG-36

Resource Type:: Conference

Resource Relation:: Conference: ASM international conference on welding and joining science and technology, Madrid (Spain), 3-10 Mar 1997; Other Information: PBD: 1997

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; METALS; LASER WELDING; WELDED JOINTS; DESIGN; ENERGY ABSORPTION

Citation Formats


                    Milewski, J O, and Sklar, E. Modeling and design of energy concentrating laser weld joints.  United States: N. p., 1997. 
        Web.

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                    Milewski, J O, & Sklar, E. Modeling and design of energy concentrating laser weld joints.  United States.

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                    Milewski, J O, and Sklar, E. 1997.  
        "Modeling and design of energy concentrating laser weld joints".  United States.  https://www.osti.gov/servlets/purl/461246.

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@article{osti_461246,

  title        = {Modeling and design of energy concentrating laser weld joints},

  author       = {Milewski, J O and Sklar, E},

  abstractNote = {The application of lasers for welding and joining has increased steadily over the past decade with the advent of high powered industrial laser systems. Attributes such as high energy density and precise focusing allow high speed processing of precision assemblies. Other characteristics of the process such as poor coupling of energy due to highly reflective materials and instabilities associated with deep penetration keyhole mode welding remain as process limitations and challenges to be overcome. Reflective loss of laser energy impinging on metal surfaces can in some cases exceed ninety five percent, thus making the process extremely inefficient. Enhanced coupling of the laser beam can occur when high energy densities approach the vaporization point of the materials and form a keyhole feature which can trap laser energy and enhance melting and process efficiency. The extreme temperature, pressure and fluid flow dynamics of the keyhole make control of the process difficult in this melting regime. The authors design and model weld joints which through reflective propagation and concentration of the laser beam energy significantly enhance the melting process and weld morphology. A three dimensional computer based geometric optical model is used to describe the key laser parameters and joint geometry. Ray tracing is used to compute the location and intensity of energy absorption within the weld joint. Comparison with experimentation shows good correlation of energy concentration within the model to actual weld profiles. The effect of energy concentration within various joint geometry is described. This method for extending the design of the laser system to include the weld joint allows the evaluation and selection of laser parameters such as lens and focal position for process optimization. The design of narrow gap joints which function as energy concentrators is described. The enhanced laser welding of aluminum without keyhole formation has been demonstrated.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/461246},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {Tue Apr 01 00:00:00 EST 1997},

  month        = {Tue Apr 01 00:00:00 EST 1997}

}

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