Deformation characteristics of plastics in YAG laser forming

Yasuhiro Okamoto, Isamu Miyamoto, Yoshiyuki Uno, Tomohiko Takenaka

Research output: Contribution to journalConference articlepeer-review

4 Citations (Scopus)


Plastic material can be also bent by laser forming in the same way as metal material, and larger bending angle can be obtained as compared to metal material. However, its deformation mechanism has not been yet clarified. Therefore, in this study, the machining characteristics and the deformation mechanism of plastic in YAG laser forming were made clear by experimental and numerical analysis. Small temperature gradient was obtained by thermal analysis in laser forming of high density polyethylene. The plastic material could be bent due to high viscoelasticity in spite of small temperature gradient. Specimen was first bent by the temperature gradient in thickness direction in a few seconds after the laser irradiation. Then, the temperature of specimen became almost the same in thickness direction, and the temperature gradient appeared only in side direction. Therefore, the deformation of specimen was occurred by the contraction of specimen in side direction and the effect of initial shape, which was deformed by the temperature gradient just after the laser irradiation. Besides, it was clarified that small thermal conductivity of plastic material lead to low cooling speed. Therefore, sufficient cooling time is necessary in order to control the deformation accurately, since the temperature of specimen should be kept equal before every laser irradiation.

Original languageEnglish
Article number93
Pages (from-to)576-581
Number of pages6
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - Dec 1 2004
EventFifth International Symposium on Laser Precision Microfabrication - Nara, Japan
Duration: May 11 2004May 14 2004


  • High density polyethylene
  • Laser forming
  • Plastic
  • Thermal analysis
  • Thermal stress
  • YAG laser

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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