Wear mechanism and quantification of polycrystalline diamond milling cutter in high speed trimming of carbon fiber reinforced epoxy

Abstract

The use of polycrystalline diamond cutters (PCD) in machining of composite material is increasing. Understanding their wear mechanism and clarity on wear measurement methodology will lead to their productive usage and cost justification. This study focuses on understanding wear in PCD milling cutters at the micro, macro level, and its physical characterization when employed for fibrous composite machining. This leads to the development of a proposal for a clear methodology on consistent wear measurement, which includes a suitable selection of techniques and identification of wear parameters. Continuous diamond skeleton structure made during binder infiltration is captured in worn out PCD edge with the help of scanning electron microscopy. Overall wear process appears to be a complex mixture of losing binder, smaller grains, and pieces of continuous diamond skeleton. This results in cavities of various shapes and forms on the cutting edge making substantial variations in edge recession and edge width. After analyzing, different tool parameters, it was found out that the distance from apex to edge roundness of clearance or rake face is a reliable and repeatable wear parameter. These are shown to be comparable between different wear locations, flutes, and tools suggesting higher wear predictive capabilities. Among different techniques, three-dimensional high-resolution profile scanning of the cutter has been identified as the most efficient tool for tracking wear at regular intervals in tool life prediction studies.