Characterization of physical processes in the process zone during free jet-based plasma electrolytic polishing

基于自由射流的等离子体电解抛光过程区域物理过程的表征

• 批准号: 536840529
• 负责人: Professor Dr.-Ing. Andreas Schubert
• 金额: --
• 依托单位: Institut für Werkzeugmaschinen und Produktionsprozesse
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/536840529?language=en
• 关键词: Characterization; physical; processes; process; zone

Jet-based plasma electrolytic polishing (Jet-PeP) enables local polishing of part sur-faces made of electrically conductive materials without need for masking and with low consumption of environmentally friendly electrolytes. It based on plasma electro-lytic polishing in a bath, where chemical-physical processes stimulate the formation of a local vapor-plasma-zone (VPZ) on the workpiece surface. This occurs when a DC electrical voltage is applied, provided a suitable combination of workpiece mate-rial, electrolyte composition and electrolyte temperature is used. This VPZ is a basic requirement for the successful initiation and continuity of the process. However, in the context of Jet-PeP, the formation and continuity of this zone has been insuffi-ciently studied and is therefore poorly understood. A specific and reproducible ad-justment of the process conditions is hardly possible, especially in case of devia-tions from the few known parameter combinations. In the present research project, the influence of the electrical and thermal energy supply on the initiation and continuity of the VPZ in the Jet-PeP process will be in-vestigated. For this purpose, the free jet is divided into characteristic zones along the flow direction of the jet. The proportions of which are investigated at the working dis-tance between the nozzle and the workpiece surface at different energy inputs. By varying the applied DC voltage, the characteristic current-voltage curves of the pro-cess initialization and the polishing process will be derived for Jet-PeP. Further-more, the influence of the flow velocity of the electrolyte jet on the formation and continuity of the VPZ in connection with the electrolyte temperature will be investi-gated. For this purpose, the electrical and thermal measurement equipment of the existing Jet-PeP setup has to be adapted and expanded. The spatial expansion of the VPZ and the process-immanent gas formation will be analyzed with a high-speed camera and image evaluation. The charge efficiency based on the electric charge of anodic dissolution and the electrolysis as well as the heat transfer between electrolyte and workpiece based on the thermal energy supply will be derived from the recording of the temporal charac-teristic of electric current and voltage as well as the electrolyte and workpiece tem-perature. The measurement analysis of the machined workpiece surfaces is used to evaluate the local polishing process and enables a differentiation between EC and PeP removal processes. Based on the experimentally received findings on the in-fluencing variables and sub-processes, it is aimed to get a first physical model for the effect of the electrical and thermal energy input on the formation of the Jet-PeP process and the VPZ.

基于射流的等离子体电解抛光（Jet-PeP）可对导电材料制成的零件表面进行局部抛光，无需掩蔽，且环境友好型电解液消耗量低。它基于在浴中的等离子体电解抛光，其中化学物理过程刺激在工件表面上形成局部蒸气等离子体区（VPZ）。这发生在施加直流电压时，只要使用工件材料、电解液成分和电解液温度的适当组合。这一VPZ是成功启动和持续开展该进程的基本要求。然而，在Jet-PeP的背景下，对该区域的形成和连续性研究不足，因此了解甚少。对工艺条件进行特定的、可重复的调整几乎是不可能的，特别是在偏离少数已知参数组合的情况下。在本研究项目中，将调查电能和热能供应对Jet-PeP工艺中VPZ的启动和连续性的影响。为此目的，自由射流沿射流的流动方向被分成沿着特征区域。在不同的能量输入下，在喷嘴与工件表面之间的工作距离处，研究了它们的比例。通过改变外加直流电压，得到了Jet-PeP抛光过程初始化和抛光过程的特征电流-电压曲线。此外，还将研究电解液射流流速对VPZ形成和连续性的影响以及与电解液温度的关系。为此，必须对现有Jet-PeP装置的电气和热测量设备进行调整和扩展。VPZ的空间扩展和工艺不稳定气体的形成将通过高速摄像机和图像评估进行分析。通过记录电流、电压、电解液温度和工件温度的时间特性，可以导出基于阳极溶解和电解过程电荷的充电效率，以及基于热能供应的电解液与工件之间的传热。加工工件表面的测量分析用于评估局部抛光过程，并使EC和PEP去除过程之间的差异。基于在影响变量和子过程上的实验接收到的发现，其目的是获得电能和热能输入对Jet-PeP过程和VPZ的形成的影响的第一物理模型。