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1993 Fiscal Year Final Research Report Summary

Studies on Optimization of Laser Materials Processing by Pulse Shaping

Research Project

Project/Area Number 03555160
Research Category

Grant-in-Aid for Developmental Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 溶接工学
Research InstitutionOsaka University

Principal Investigator

MATSUNAWA Akira  Welding Research Institute, Osaka University, Professor, 溶接工学研究所, 教授 (20029119)

Co-Investigator(Kenkyū-buntansha) MIYATA Osamu  Nippon Denso Co.Ltd., No.1 Production Engineering Division, Manager, 第1生産技術部, 係長
UCHIDA Takahiro  Miyachi Technos Co.Ltd., R&D Division, Manager, 開発部, 課長
SAITOH Minoru  Miyachi Technos Co.Ltd., R&D Division, Senior Manager, 開発部, 次長
KATAYAMA Seiji  Welding Research Institute, Osaka University, Assistant, 溶接工学研究所, 助手 (10144528)
TAKEMOTO Tadashi  Welding Research Inst., Osaka University, Associate Professor, 溶接工学研究所, 助教授 (60093431)
Project Period (FY) 1991 – 1993
KeywordsLaser / Pulsed Laser / Laser Welding / Pulse Shaping / Porosity / Solidification Crack / Rapid Solidification / Microsegregation
Research Abstract

1) Determination of Optimum Pulse Shape for Laser Processing (Conducted by A.Matsunawa and S.Katayama)
Austenetic stainless steels and aluminium alloys are known as difficult materials for welding because of formations of various defects such as porosity and crack formations, particularly, in pulsed laser welding. In ordert to eleiminate or suppress these defects, theoretical and experimental works were conducted by considering laser irradiation conditions as well as material's constants, and optimum pulse shape and its allied parameters for each material were determined to drastically eliminate defects formation.
2) Fusion and Solidification Characteristics of Pulse Shaped Laser Welding and Construction of Mathematical Model (Conducted by A.Matsunawa, T.Takemoto and S.Katayama)
Mathematical models of fusion and solidification of conduction mode laser spot welding and microsegregation of laser rapidly quenched weld metal were developed considering the latent heat of fution, and the calcul … More ated growth rate of dendrite and distribution of microsegregation were experimentally verified. The developed models were proved to be effective to predict the optimum shape to suppress the solidification crack.
3) Application of Pulse Shaped YAG Laser to Welding of Automotive Parts used Free Cutting Stainless Steel (Conducted by S.Katayama and O.Miyata)
In free cutting stainless steels, elements such as Sulpher and Bismas are added to the metal to improve the cutting propertiy but it greatly deteriorates the weldability in fusion welding because of solidification cracking. In this work, the newly developed pulse shaped YAG laser welding was applied to weld the free cutting stainless steel to ordinary austenetic stainless steel in automotive part, and crack free weld was obtained successfully.
4) Optimization and Improvement of Power Source of Pulse Shapable YAG Laser and Beam Delivery by Optical Fiber (Conducted by A.Matsunawa, M.Saitoh and T.Uchida)
A power source which enabled the pulse shaping of YAG laser was developed and optimized its circuit constants by actual welding, and also improved a beam delivery system by optical fiber to obtain the optimum power density distribution at the focal point. Less

  • Research Products

    (19 results)

All Other

All Publications (19 results)

  • [Publications] S.Katayama and others: "Laser Rapid Slidification Microstructure and Micro-segregation of Aluminum Alloy Single Crystals" Proc.of LAMP'92,May,1992,Nagaoka,Japan. Vol.1. 361-366 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Simidzu and others: "Pulsed Nd:YAG Laser Spot Welding of Aluminum Alloys" Proc.of LAMP'92,May,1992,Nagaoka,Japan. Vol.1. 511-516 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A.Matsunawa and others: "Effect of Pulse Shaping on Defect Reduction in Pulsed Laser Welding" Proc.of ICALEO'92,Nov.1992,Orlando,FL,USA. Vol75. 547-556 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A.Matsunawa and others: "Fusion and Solidification Characteristics in Pulse-Shaped YAG Laser Welding" Proc.of 5th CISFFEL,June,1993,Laboul,France. Vol.1. 219-226 (1993)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 松縄 朗、他3名: "パルスレーザ照射部の溶融・凝固に関する数値計算モデル" 溶接学会全国大会講演概要集. 第51集. 120-121 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 松縄 朗、他5名: "アルミニウム合金のYAGレーザ溶接性に及ぼすパルス波形の影響" 溶接学会全国大会講演概要集. 第51集. 142-143 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S.Katayama and others: "Laser Rapid Solidification Microstructure and Micro-segregation of Aluminum Alloys Single Crystals" Proc.of LAMP'92, May, 1992, Nagaoka, Japan. Vol.1. 361-366 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] H.Simidzu and others: "Pulsed Nd : YAG Laser Spot Welding of Aluminum Alloys" Proc.of LAMP'92, May, 1992, Nagaoka, Japan. Vol.1. 511-516 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Effect of Pulse Shaping on Defect Reduction in Pulsed Laser Welding" Proc.of ICALEO'92, Nov., 1992, Orlando, FL., USA. Vol.75. 547-556 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Fusion and Solidification Characteristics in Pulse-Shaped YAG Laser Welding" Proc.of 5th CISFFEL, June, 1993, Laboul, France. Vol.1. 219-226 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Mathematical Modeling of Fusion and Solidification in Pulsed Laser Spot Welding (in Japanese)" Preprints of Annual Meeting of Japan Welding Society (JWS). Vol.51. 120-121 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] S.Katayama and others: "Solidification Behavior in Pulsed Laser Spot Welding of Pure Metals and Alloys (in Japanese)" Preprints of Annual Meeting of JWS. Vol.51. 124-125 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Effect of Pulse Shape on YAG Laser Weldability of Aluminium Alloys (in Japanese)" Preprints of Annual Meeting of JWS. Vol.51. 142-143 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Prevention of Weld Defects of Aluminium Alloys by Pulse Shaping of YAG Laser (in Japanese)" Preprints of Annual Meeting of High, Temperature Society of Japan (HTSJ). Vol.19. N53-N54 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Prediction of Fusion and Solidification of Conduction Mode Welding by Pulse Shaped Laser (in Japanese)" Preprints of Annual Meeting of JWS. Vol.53. 104=105 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Generation and Prevention of Welding Defects of Stainless Steels in Laser Welding (in Japanese)" Preprints of Annual Meeting of JWS. Vol.53. 110-111 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Fusion and Solidification Phenomena in Pulsed Laser Welding of Stainless Steel (in Japanese)" Preprints of Annual Meeting of JWS. Vol.53. 112-113 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Matsunawa and others: "Crack Prevension of Aluminium Alloys by Pyulse Shape Control in Laser Welding (in Japanese)" Preprints of Annual Meeting of JWS. Vol.53. 120-121 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] H.Simidzu and others: "Spot Welding of Aluminium Alloys by Pulsed YAG Laser (in Japanese)" Preprints of Annual Meeting of JWS. Vol.53. 122-123 (1993)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1995-03-27  

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