Studies on Optimization of Laser Materials Processing by Pulse Shaping

脉冲整形优化激光材料加工的研究

• 批准号: 03555160
• 负责人: MATSUNAWA Akira
• 金额: $ 8万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03555160/
• 关键词: Laser; Pulsed Laser; Laser Welding; Pulse Shaping; Porosity; Solidification Crack; Rapid Solidification; Microsegregation; 波系制御; レーザー; レーザー加工; パルスレーザー; レーザープラズマ; 逆制動放射; 散乱; 溶接欠陥; 高温割れ; レ-ザ-; レ-ザ-加工; パルスYAGレ-ザ-; パルス発振波形; ポロシティ; スポット溶接

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

1) 确定激光加工的最佳脉冲形状（由 A.Matsunawa 和 S.Katayama 进行） 奥氏体不锈钢和铝合金由于会形成各种缺陷（例如气孔和裂纹形成），特别是在脉冲激光焊接中，因此被称为难以焊接的材料。为了消除或抑制这些缺陷，通过考虑激光照射条件以及材料常数进行了理论和实验工作，并确定了每种材料的最佳脉冲形状及其相关参数，以彻底消除缺陷的形成。2）脉冲形状激光焊接的熔化和凝固特性以及数学模型的构建（由A.Matsunawa，T.Takemoto和 S.Katayama)建立了考虑熔化潜热的传导型激光点焊熔化和凝固以及激光快淬焊缝金属微观偏析的数学模型，并通过实验验证了计算得到的枝晶生长速率和微观偏析分布。所开发的模型被证明可以有效地预测抑制凝固裂纹的最佳形状。3）脉冲型YAG激光在易切削不锈钢汽车零件焊接中的应用（由S.Katayama和O.Miyata进行）在易切削不锈钢中，在金属中添加Sulpher和Bismas等元素以改善切削性能，但它大大恶化了熔化时的可焊性 焊接时由于凝固裂纹。本工作采用新开发的脉冲整形YAG激光焊接技术，将易切削不锈钢与普通奥氏体不锈钢焊接在汽车零部件上，并成功获得了无裂纹焊缝。4)脉冲整形YAG激光器电源和光纤光束传输的优化和改进（由A.Matsunawa、M.Saitoh和T.Uchida负责） 开发了YAG激光器的整形技术，并通过实际焊接优化了其电路常数，并改进了光纤光束传输系统，以获得焦点处的最佳功率密度分布。较少的

项目成果

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)

A.Matsunawa等：“脉冲型YAG激光焊接中的熔化和凝固特性”Proc.of 5th CISFFEL，1993年6月，Laboul，法国。

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)

A.Matsunawa等：“脉冲整形激光传导模式焊接的熔化和凝固预测（日文）”JWS年会预印本。

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)

A.Matsunawa等人：“激光焊接中通过Pyulse形状控制来预防铝合金的裂纹（日文）”JWS年会预印本。

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)

S.Katayama等：“纯金属和合金的脉冲激光点焊中的凝固行为（日文）”JWS年会预印本。

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)

Akira Matsunawa，其他 5 人：“脉冲波形对铝合金 YAG 激光焊接性的影响”日本焊接学会全国会议演讲摘要 51. 142-143 (1992)。