セラミックスのレーザ溶接　Ｉ　　ビード形状と溶接欠陥について

• 丸尾 大

  大阪大学工学部

• 宮本 勇

  大阪大学工学部

• 井上 良彦

  大阪大学工学部

• 荒田 吉明

  大阪大学溶接工学研究所

書誌事項

タイトル別名

• CO<SUB>2</SUB> Laser Welding of Ceramics (Report 1)
• ビード形状と溶接欠陥について

抄録

A C0₂ laser was applied for welding A1₂O₃-SiO₂ sintered ceramics with 48-99.5 wt% alumna contents. The effects of welding parameters and preheating temperature on the bead shape, penetration depth and weld defects including underfill of the bead, porosity and cracking were discussed. The results obtained are summarized as follows:<BR>(1) Paralled-sided and deeply penetrated beads were obtained in mullite ceramics and the penetration depth, which is inversely proportional to the welding speed, was deeper than that of laser welding of SUS304. In high alumina ceramics, a wine-cup bead was resulted from the laser-produced plasma. The differences in welding characteristics between ceramics and metals were discussed on the basis of the welding mechanism.<BR>(2) Underfill due to material vaporization is remarkable when the depth-to-width ratio of the bead is one, resulting in around 75 % of heat loss, whereas the underfill is sufficiently small when the focal position is on the workpiece surface.<BR>(3) Porosities were formed along the fusion boundary in low alumina mullite and in the nail head of the bead in high alumina ceramics.<BR>(4) When the preheating temperature is not high enough, there appeared two types of weld-cracks; a transverse crack, which 'propagates perpendicularly to the bead and a longitudinal crack; which propagates parallelly to the.bead from-the bottom surface.<BR>(5) At high welding speeds, the transeverse crack is prevented at the preheating pemperature Tt, where the materials have plasticity; Tt is 1000°C in mullite; 1200°C in 95wt%A1₂O₃; 1400°C in 99.5wt% A1₂O₃. At low welding speeds, transverse crack can be prevented by widening the heat affected zone at preheating temperatures down to 600°C in low alumina mullite.The longitudinal crack occurs around critical speeds for full-penetration welding, and can be prevented at preheating temperatures 200°C higher than Tt.

収録刊行物

• 溶接学会誌

  溶接学会誌 51 (2), 182-189, 1982

  一般社団法人 溶接学会

キーワード

• Metals and Alloys
• Surfaces, Coatings and Films
• Mechanical Engineering
• Mechanics of Materials

詳細情報

• CRID: 1390001206499761408
• NII論文ID: 130003763639
• DOI: 10.2207/qjjws1943.51.182
• ISSN: 18837204
• ISSN: 00214787
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可