摘要
Laser chemical machining(LCM)is a gentle metal removal technique with micrometer resolution.LCM involves laser-driven surface heating of the workpiece,which is subjected to a flowing acid bath,locally inducing a chemical dissolution reaction.To ensure a high machining quality,the laser power is intentionally limited to avoid disturbances in material removal presumably caused by the shielding effect of boiling bubbles.To achieve both an increased removal rate and a high removal quality,the current understanding of surface removal mechanisms must be fundamentally expanded.Therefore,to create the basis of near-process quality control in the future,a near-process measurement approach is needed for the machined workpiece geometry inside the machine and the temperature in the process fluid as an important process quantity.This study introduces a fluorescence-based measurement approach capable of assessing both quantities in-situ.An experimental feasibility study demonstrated the robustness of the approach in measuring the three-dimensional geometry of a structure produced by LCM,even in the presence of streaming air bubbles in the optical path,thereby validating its near-process capability.However,systematic measurement errors,such as edge artifacts,were observed in the geometry measurements,indicating the need for a revision of the signal model.In addition,precise temperature measurements of the electrolyte solution within the LCM environment were achieved,with a random error of 1℃ and a systematic error of 1.4℃.
基金
Contributions by Claudia Niehaves,Yasmine Bouraoui,Yang Lu and Tim Radel are funded by the German Research Foundation(DFG),project number 451385285(Process-oriented characterization of temperature field and ablation changes during laser chemical processing)
Andreas Tausendfreund was funded by the European Research Council(ERC),project number 101044046-InOGeM(Indirect Optical Geometry Measurement).
