振荡扫描激光束-电弧复合焊接的过程控制与冶金行为研究

项目名称： 振荡扫描激光束-电弧复合焊接的过程控制与冶金行为研究

项目编号： No.51275186

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 机械、仪表工业

项目作者： 高明

作者单位： 华中科技大学

项目金额： 80万元

中文摘要： 研究发现，激光-MIG电弧复合焊接中厚铝合金必须采用大电弧电流来抑制焊缝气孔，这导致热输入较大，接头强韧性不够理想。为此，本项目提出基于振镜的振荡扫描激光束-电弧复合焊接铝合金新工艺、新方法：利用激光束的高频扫描强制搅拌熔池，该搅拌效应和激光-电弧相互作用能够优势互补，实现既消除焊缝气孔又改善焊缝组织、提高接头强韧性的目的。本项目将围绕其中的关键科学问题进行研究，揭示激光束高频振荡扫描的动态行为对电弧特性和激光-电弧相互作用的影响规律；探索由高频振荡扫描激光束驱动的熔池搅拌效应和熔体有序流动对熔池传热传质、合金元素烧损迁移、缺陷形成、焊缝结晶等焊接冶金行为的影响规律，及其和接头组织性能的内在关联。在此基础上，提出铝合金振荡扫描激光束-MIG复合焊接过程控制和接头组织性能的调控方法，建立工艺参数数据库系统，为铝合金的高质量焊接提供理论依据和技术支撑，并丰富激光-电弧复合焊接基础理论。

中文关键词： 1振荡扫描激光束；激光-电弧复合焊接；铝合金；气孔；力学性能

英文摘要： Based on the previous finding that high arc current must be used to advoid the pore formation within the weld during laser-arc hybrid welding of thick aluminum alloys, which is very adverse to improve the joint mechanical properties including strength and toughness due to the high heat input, we put forward to a new idea named as oscillating laser beam-arc hybrid welding based on high frequency laser beam oscillator to overcome this quesiton. During this new hybrid welding, the regularly oscillating laser beam would stir the molten pool to refine the grains and improve the uninformity of the weld microstructure as the laser-arc interaction reduces the weld porosity. By the syniergic effect of the stirring impact induced by osicillating laser beam and the laser-arc interaction of hybrid welding, not only the weld porosity can be well avoided but also the joint mechanical propertes can be improved. This study aims to investigate the effects of the high frequency osicillating of laser beam on the arc characteristics, dorplet transfer and laser-arc interaction during hybrid welding, explore the effects of the strong stirring and regular melt flow indcued by laser beam oscillating on the compicalted metallurgical behaviors in molten pool including heat and mass transfer, burning-loss and migration of alloying element

英文关键词： Oscillating laser beam；Laser-arc hybrid welding；Aluminum alloy；Porosity；Mechanical properties