Micro-milling tool wear monitoring through a novel method for burrs evaluation

摘要

Due to the high performances it assures, micro-milling is increasingly used in the production of miniaturized components in many different fields, such as automotive, aerospace and biomedical. This technology is characterized by high material removal rate, high flexibility and the possibility to machine different metal alloys in complex 3D shape. However, micro-milling may produce three-dimensional burrs, which represent one of the major issues of this manufacturing process. When micro machining, burrs size are of the same magnitude of the cutting tool diameter, therefore their effects have to be taken into consideration for the overall effectiveness of the process. Thus, burrs may represent a huge problem; moreover, because of their correlation with tool wear, their quantification could be useful as an indicator for process control. This work is focused on the application to a slotting micro-milling operation of a newly developed method for fast, non-destructive and in-line evaluation of multiple geometrical parameters related to the slot quality. The methodology includes the quantification of the lateral distribution of burrs based on an unconventional use of void pixels resulting from limitations of optical microscopy, as well as quantification of the actual depth of cut and surface texture parameters. These multiple indicators allow monitoring the tool wear effects on machined surface quality to ensure a controlled output of the machining process.