Surface finish improvement using a damping-alloy sleeve-insert tool holder in the end milling process

This study investigates the effect of a tool holder with a metallic damping alloy on both vibration reduction and surface finish improvement for use in an end-milling process. Two different configurations of damping alloys are designed: a collet and a sleeve inside a conventional tool holder. To determine the system characteristics including damping effects, an experimental verification was organized, after that actual machining tests are conducted. The damping effects of each tool holder are compared through machining tests on carbon-fiber reinforced plastics (CFRP) and mold steel respectively. Additionally, a chatter vibration suppression test using thin aluminum workpiece concludes that the metallic damping alloy is comparable to other damping methods. The results show that damping alloy can reduce machining vibration regardless of workpiece materials or the form of it, and the sleeve type tool holder improves the surface roughness significantly in an end-milling process for both workpiece materials.