权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Increase in process efficiency of laser chemical machining by preventing the gas bubble related removal disturbances

通过防止与气泡相关的去除干扰来提高激光化学加工的工艺效率

基本信息

批准号：
403820352
负责人：
Professor Dr.-Ing. Frank Vollertsen
金额：
--
依托单位：
BIAS - Bremer Institut für Angewandte Strahltechnik GmbH
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/403820352?language=en
关键词：
Increase process efficiency laser chemical

项目摘要

Laser chemical machining (LCM) is a further development of the electrochemical processing and is based on the laser-induced anodic material dissolution at the interface workpiece-electrolyte. Thereby, the process is characterized by its flexibility and variety, its gentle and residue-free removal as well as its low thermal load on the workpiece. Using suitable material-electrolyte combinations and energy inputs structures of < 50 μm and surface roughness of up to 0.1 μm can be realized. However, the low processing speed (<1·e-2 mm3/min) is still representing the main disadvantage of LCM-process and poses an obstacle for an industrial application. This can be reduced to the fact that purely laser chemical machining takes place in a very restricted process window, which is limited by the rapid achievement of the electrolyte boiling point. Due to high induced temperatures the intensified formation of boiling bubbles exerts a shielding effect in the interaction zone and leads to a disturbance of the material removal.The aim of this project is therefore to further increase process efficiency and quality of the laser chemical removal. In order to avoid the formation of gas bubbles the process should be carried out in higher ambient pressures. Thereby it is assumed that the increase of the electrolyte boiling point due to rising ambient pressure leads to a reduction in gas bubble size as well as to an increase in the removal rates. Thus, the process window for disturbance-free laser chemical removal can be broadened.For this purpose, a suitable process cell should be developed to ensure a safe processing at high ambient pressures. In dependence of the process relevant parameters, e.g. ambient pressure the properties of the laser chemical removal (removal depth, width, and surface quality) should be then characterized. Besides, the pressure-dependent process windows, within which a disturbance-free removal can be realized reproducibly, are to be identified. For a better understanding of the removal mechanisms the temperature-related transitions of the boiling regimes as well as the behavior of the interaction zone with and without laser beam exposure should be visualized. Thus, the relationships between the boiling properties and the resulting removal disturbances could be demonstrated and clarified. The findings to be obtained should then feed into a model-like description of the LCM removal mechanisms, which should be based on the analytical computation of the laser-induced temperature fields on the workpiece surface and their direct correlation with the resulting removal geometries.

激光化学加工是电化学加工技术的进一步发展，它是基于激光诱导阳极材料在工件-电解液界面溶解的原理。因此，该工艺具有灵活性和多样性、温和且无残留物的去除以及对工件的低热负荷等特点。使用合适的材料-电解质组合和能量输入，可以实现< 50 μm的结构和高达0.1 μm的表面粗糙度。然而，低加工速度（<1·e-2 mm 3/min）仍然是LCM工艺的主要缺点，并且对工业应用构成障碍。这可以归结为这样一个事实，即纯激光化学加工发生在非常有限的工艺窗口中，这受到电解质沸点快速达到的限制。由于诱导温度高，沸腾气泡的强化形成在相互作用区产生屏蔽效应，并导致材料去除的干扰。因此，本项目的目的是进一步提高激光化学去除的工艺效率和质量。为了避免气泡的形成，该过程应在较高的环境压力下进行。因此，假设由于环境压力上升而导致的电解质沸点的增加导致气泡尺寸的减小以及去除速率的增加。为此，需要开发一种合适的加工单元，以确保在高环境压力下的安全加工。根据工艺相关参数，例如环境压力，然后应表征激光化学去除的特性（去除深度、宽度和表面质量）。此外，压力依赖的过程窗口，在其中可以实现可重复的无干扰的去除，被识别。为了更好地理解去除机制，应该可视化沸腾状态的温度相关转变以及有和没有激光束曝光的相互作用区的行为。因此，沸腾特性和由此产生的去除扰动之间的关系可以被证明和澄清。要获得的调查结果，然后应馈入LCM去除机制，这应该是基于工件表面上的激光诱导的温度场的分析计算和它们的直接相关性与所产生的去除几何形状的模型般的描述。