Surface related features of laser welding of aluminium alloys
Surface related features of laser welding of aluminium alloys
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铝合金激光焊接的表面相关特征
DOI：
10.2355/isijinternational.40.suppl_s6
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发表时间：
2000
影响因子：
1.8
通讯作者：
J. Weston
中科院分区：
文献类型：
--
作者：
J. Weston
进行了一项研究计划，以调查铝合金激光焊接工艺参数的依赖性。采用四种不同的激光系统：二氧化碳（CO2）、一氧化碳（CO）、脉冲钕钇铝石榴石（Nd：YAG）和高功率连续Nd：YAG激光器，本文描述了熔池和小孔表面发生的现象，从激光束到工件的能量传递，称为耦合，是决定焊接热输入的关键因素，这是主要的工艺变量之一。这种多部分转移所涉及的物理机制是复杂的，因此采取实验路线来确定耦合及其对激光和材料特性的依赖性。测量了五种铝合金和四种激光系统的耦合。激光焊接中发现的高表面温度导致某些合金元素的优先蒸发。通过研究用一系列激光系统进行的焊接，可以观察到这种效果对工艺参数的依赖性。高蒸发率也被发现与激光焊接中出现的另一个问题--自生焊缝中的根切有关。
A program of research was carried out to investigate the dependence of laser welds in aluminium alloys upon proces parameters. Four different laser systems were used: carbon dioxide (CO2), carbon monoxide (CO), pulsed neodymium yttrium aluminium garnet (Nd:YAG) and high powered continuous Nd:YAG lasers.This paper describes phenomenon that occur at the surface of the weld pool and keyhole.The energy transfer from the laser beam to the workpiece, termed the coupling is a crucial factor in determining the heat input to the weld which is one of the major process variables. The physical mechanisms involved in this multi-part transfer are complex, hence an experimental route was taken to determine the coupling and its dependence upon laser and material properties. Coupling was measured for the combinations of five aluminium alloys and four laser systems.The high surface temperatures found in laser welding result in preferential evaporation of certain alloying elements. By studying welds made with a range of laser systems, the dependence of this effect upon process parameters could be observed. The high evaporation rates were also found to be linked to another problem that arises in laser welding-that of undercutting in autogenous welds.Porosity was observed and is discussed here in terms of its mechanism of formation.