| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 99 === Micro mechanical cutting draw much more attention with the increase of demand on the micro feature devices. However, the weakness of micro tool makes it easy to be worn out and how to improve the tool life becomes an important task in developing the micro mechanical cutting technology. Therefore, the tool coated with diamond thin film provides a potential solution to improve the tool life and cutting efficiency in micro cutting.
In this study, the diamond coated WC micro tool was implemented on the micro machining research platform in machining the graphite to investigate the effect of diamond thin film on tool life, cutting force, and surface roughness, as well as the application of the Acoustic Emission (AE) signal on monitoring the film delamination.
The results show that the size effect was observed when the micro tool was coated with two levels of diamond thin film, especially in Y direction, but not in the case with un-coated micro tool. As for the tool life improvement, over 10 times of the tool life was observed for diamond coated tool than un-coated micro tool. By the way, the cutting force increased as tool wear proceed for un-coated tool. However, the change of cutting force was not observed clear for diamond coated tool as tool wear increase, but the cutting force increases significantly as the delamination of the diamond film occurs.
In investigating the AE signal change as coated film delaminated, the energy change in the time and frequency domain is observed. As for the cutting performance, the effect by the cutting speed is observed to be higher than that by the feed rate. Finally, no effect can be observed significantly by the change of the spiral angle of micro tool.
|
|---|
