Optimization of micro milling processes through controlled vibration of workpiece

用于模具制造的微铣削是一种成熟的制造工艺。可以说，医疗和生物技术组件和应用的利用率越来越高。与激光烧蚀或电火花加工（EDM）等其他微制造工艺相比，它具有工件形状灵活性高和加工时间短的特点。加工性能主要受工件硬度和相应的刀具磨损的限制。此外，在非常小的碎屑厚度下的犁削效应对工艺结果具有负面影响。过早的刀具断裂和表面粗糙度差的后果。本研究旨在借由振动辅助微细铣削辅助装置之实现，以达到工艺最佳化之目的。工件在水平于主轴轴线的两个方向上被激励。根据机床主轴的旋转角度来控制致动器振荡的频率、振幅和相移。因此，真实的时间环境连接到集成有致动器的工件支撑件以及机床的控制系统。通过改变振荡信号，可以系统地设置不同的工艺条件。工艺结果进行了研究，可实现的表面粗糙度，刀具磨损和表面形貌。实验验证伴随着建模产生的切削刃轨迹。由此，可以实现通过微铣削的可再现的表面结构化。

Micro milling for die and mould fabrication is a well-established manufacturing process. An increasing utilization for medical and biotechnical components and applications can be stated. Compared to other micro manufacturing processes such as laser ablation or electrical discharge machining (EDM) it is characterized by high flexibility for work piece shapes and low process time. The process performance is mainly limited by the work pieces hardness and the according tool wear. Also, ploughing effects at very small chipping thickness have negative effects on the process result. Premature tool breakage and bad surface roughness are the consequences. This research project aims to a process optimization by implementing an auxiliary device for vibration assisted micro milling. The work piece is excited in two directions horizontally to the spindle axis. Frequency, amplitude and phase shift of the actuator oscillation are controlled according to the rotational angle of the machine tool spindle. Therefore a real time environment is connected to the actuator integrated work piece support as well as to the control system of the machine tool. By varying the oscillation signals different process conditions can be set systematically. Process results are investigated in terms of achievable surface roughness, tool wear and surface topography. The experimental verifications are accompanied by modelling the resulting cutting edge trajectories. By that, reproducible surface structuring by micro milling can be enabled.