Development and analysis of all-ceramic micro end mills with diameters ≤ 50 µm

直径≤50 µm全陶瓷微型立铣刀的研制与分析

• 批准号: 407558930
• 负责人: Professor Dr.-Ing. Jan C. Aurich
• 金额: --
• 依托单位: Lehrstuhl für Fertigungstechnik und Betriebsorganisation (FBK)
• 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 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407558930?language=en
• 关键词: Development; analysis; ceramic; micro; end

Micro milling offers significant advantages compared to other micro machining methods. These advantages are the high range of machinable materials, the achievable geometric complexity as well as the high surface quality. Today, end mills with diameters ≤ 50 µm are almost exclusively made of cemented carbide, due to its good material properties and machinability.However, the low tool diameters of the cemented carbide tools lead to a reduction of tool stability, while the specific cutting forces increase disproportionately. Furthermore, due to the increasing influence of the cutting edge radius, the so-called ploughing-effect occurs, which means that the workpiece material is pressed underneath the cutting edge and pushed through without being cut. In addition to a deterioration of the surface quality and increasing burr formation, the ploughing-effect leads to increased process forces and a strong wear of the filigree micro tool. Due to the microstructure and the grain size of the cemented carbides used, the minimum cutting edge radii of the tools is limited by the grain size of ultra-fine-grained carbides (0.2 µm).Caused by their microstructure, using ceramics as cutting material can further reduce the achievable cutting edge radii of the tools and thus the occurring process forces. In addition, ceramics have a higher hot hardness and wear resistance than cemented carbides, but are currently not applied for milling tools with tool diameters ≤ 50 μm.The overall goal of the research project is the first-time development and application of fully ceramic micro milling tools with diameters ≤ 50 μm. In analogy to macro cutting tools, the novel ceramic end mills are expected to reduce tool wear. In addition, improved surface quality of the workpieces, reduced burr formation and a higher tool life are expected. For this purpose, suitable cutting ceramics are selected and analogy tests for wear investigations are carried out. On this basis, the tool geometry of the fully ceramic end mills is developed by numerical and kinematic simulation. The micro end mills produced via grinding are used for milling tests. The results are compared with milling results of existing cemented carbide end mills produced in the proposer’s lab.

与其他微加工方法相比，微铣削具有显着的优势。这些优点是可加工材料的范围广，可实现的几何复杂性以及高表面质量。目前，直径≤ 50 µm的立米尔斯铣刀几乎全部由硬质合金制成，因为硬质合金具有良好的材料性能和可加工性。然而，硬质合金刀具的刀具直径较小，导致刀具稳定性降低，而比切削力不成比例地增加。此外，由于切削刃半径的影响越来越大，出现了所谓的犁削效应，这意味着工件材料被压在切削刃下方并被推过而不被切削。除了表面质量的恶化和增加毛刺的形成之外，犁削效应导致增加的加工力和细丝微工具的强烈磨损。由于所使用的硬质合金的微观结构和晶粒尺寸，刀具的最小切削刃半径受到超细晶粒碳化物（0.2 µm）晶粒尺寸的限制。由于其微观结构，使用陶瓷作为切削材料可以进一步减小刀具可实现的切削刃半径，从而减少发生的加工力。此外，陶瓷具有比硬质合金更高的热硬度和耐磨性，但目前还没有应用于刀具直径≤ 50 μm的铣刀。该研究项目的总体目标是首次开发和应用直径≤ 50 μm的全陶瓷微铣刀。与宏观切削刀具类似，新型陶瓷端米尔斯有望减少刀具磨损。此外，还可提高工件的表面质量，减少毛刺的形成，并延长刀具寿命。为此，选择了合适的切削陶瓷，并进行了磨损模拟试验研究。在此基础上，通过数值模拟和运动学仿真，确定了全陶瓷立米尔斯铣刀的刀具几何形状。采用磨削加工的微型立米尔斯铣刀进行铣削试验。并将计算结果与实验室生产的现有硬质合金立米尔斯铣刀的铣削结果进行了比较。