Comparing the Performance of Diamond Coated and Uncoated Micro End Mills Using Robustness Testing

The objective of this work is to compare the performance of uncoated micro end mills with micro end mills coated using various pretreatments and diamond coatings. Testing is conducted with 300-um-diameter, two-flute, carbide end mills cutting full-width slots in 6061-T6 aluminum. The comparison of these tools is conducted with a robustness test where the feed rate of the tool is increased every 5 mm of linear travel until catastrophic tool failure occurs. The outcomes from these tests are the maximum chipload, therefore material removal rate, and the maximum force experienced by the tool. It has been determined that tools pre- treated with an acid etch have a statistically lower maximum chipload than as-received tools. However, all other pretreatments and as-received tools had statistically equivalent maximum chiploads. Further improvements in the robustness testing method are needed to reduce data scatter and better test for differences in the tool coating methods.