Experimental and Theoretical Analysis of Deep Penetration Welding Processes with Low-Power Laser-Assisted Plasma Arcs

低功率激光辅助等离子弧深熔焊接工艺的实验和理论分析

基本信息

批准号：
263050501
负责人：
Professor Dr.-Ing. Eckhard Beyer
金额：
--
依托单位：
Professur für Fügetechnik und Montage
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/263050501?language=en
关键词：
Experimental Theoretical Analysis Deep Penetration

项目摘要

This research project aims at the further improvement of our current knowledge about laser-assisted plasma arc welding processes with particular consideration of the experimentally verified deep penetration effect at low laser beam intensities and low arc currents. Firstly, the processing conditions are to be identified by means of bead-on-plate welding trials for different types of metals such as iron, aluminum, magnesium, titanium or their alloys. Secondly, it is intended to reveal the most relevant interaction mechanisms being responsible for the transfer into the deep penetration welding regime by particular experimental and theoretical approaches. For the first time, new research hypotheses, concerning possible changes of the energy transfer efficiency and of thermal and fluid-mechanical interactions during laser-assisted plasma arc welding, will be verified. This involves investigations of beam absorption, arc root formation and preheating effects under conditions of deep penetration welding. Furthermore, the impact of changes in ambient pressure distribution and local flow fields, induced by the arc flow in interaction with laser-induced evaporation processes, on the deep penetration effect are to be characterized. A self-developed coaxial arrangement of the laser beam and the plasma arc, which directs the laser beam through a thin hollow tungsten cathode, will be applied for the laser-assisted plasma arc welding trials. In addition, different experimental setups are designed for detailed investigations of possible interaction phenomena. Adapted numerical simulation models support the evaluation of effects that cannot be directly observed by experimental methods. As a result, the most important interaction mechanisms in laser-assisted plasma arc welding will be identified. With the improved process understanding, guidelines for optimal parameter settings for laser-assisted plasma arc welding can be derived, depending on the particular properties of the material being welded.

该研究项目旨在进一步提高我们目前有关激光辅助等离子弧焊接工艺的知识，特别是考虑到在低激光束强度和低电弧电流下经过实验验证的深熔深效应。首先，通过对铁、铝、镁、钛或其合金等不同类型的金属进行板焊试验来确定加工条件。其次，旨在通过特定的实验和理论方法揭示导致深熔焊接状态转变的最相关的相互作用机制。首次验证关于激光辅助等离子弧焊接过程中能量传输效率以及热和流体机械相互作用可能发生的变化的新研究假设。这涉及深熔焊接条件下的光束吸收、电弧根部形成和预热效果的研究。此外，还需要表征由电弧流与激光诱导蒸发过程相互作用引起的环境压力分布和局部流场的变化对深穿透效应的影响。激光辅助等离子弧焊接试验将采用自行开发的激光束和等离子弧同轴布置，引导激光束穿过薄空心钨阴极。此外，还设计了不同的实验装置来详细研究可能的相互作用现象。适应的数值模拟模型支持对实验方法无法直接观察到的效果进行评估。因此，将确定激光辅助等离子弧焊中最重要的相互作用机制。随着对工艺的理解不断加深，可以根据被焊接材料的具体特性得出激光辅助等离子弧焊最佳参数设置的指南。