Parent Material Surface Deposits Origin in Finish Turning Operations of the Powder Processed Nickel Based Superalloy RR1000

The origin of material surface deposits, often denoted as pick-up, on finish turned advanced nickel based superalloy RR1000 has been investigated. Three types of pick-up were defined: streaks of chip residue producing relatively low surface roughness changes, minor pick-up deposits ranging in length from 10-100 μm, and major pick-up deposits ranging in length from 200-500 μm leading to significant protrusions. Pick-up occurrence in turning operations was linked to the fracture of primary and secondary serrations forming at the chip’s trailing edge, whilst it was found that the selection of machining parameters and the workpiece ductility performance were key factors for influencing pick-up severity.