Tool life improvement using a shim with nanostructured composite damping coating synthesized by high power impulse magnetron sputtering

Sammanfattning: The thesis made an investigation of the damping treatment on cutting inserts for reducing the high frequency vibrations and improving the tool life. The damping coating of Cr:CuCNx has a multiple layer structure, and was synthesized by high power impulse magnetron sputtering (HIPIMS) method. Comparisons between coated and uncoated shims were carried out under stable turning conditions. The measured acceleration signals showed that the vibration amplitude on high frequency range between 3000 Hz and 22000 Hz on the tool holder was reduced by 30%-50% by using a shim coated with the nanostructured composite material. The flank wear was 193 μm after 32 minutes tuning process for the insert having the damping coating shim, versus 264 μm flank wear of a conventional shim under the same condition. However, the surface roughness of workpiece showed the only marginal difference between the damping coated shim and the conventional shim.