Research on tool wear morphology and mechanism during turning nickel-based alloy GH4169 with PVD-TiAlN coated carbide tool

Abstract

Tool wear affects tool life, dimensions, etc. However, tool wear mechanism was mainly studied by the relevant references in the sharp wear stage, and tool wear morphology and mechanism were not completely understood in the initial and steady wear stage. Tool wear investigation of coated carbide tool is carried out during turning GH4169 in dry cutting. Tool wear microscopic morphology, tool wear curve, tool cutting force and tool wear mechanism are studied during turning GH4169 in the initial, steady and sharp wear stage. Tool wear mechanism in the sharp wear stage is further investigated by SEM, EDS, XPS and XRD. Doing so helps to test and improve the quality of the tool coating and substrate material, helps to gain a deep understanding of the difficult-to-machine characteristics of GH4169, and helps to guarantee the dimensional accuracy and surface quality of the workpiece. Results show that serious abrasive wear, tool nose wear and adhesive wear occurred in the whole wear stage. The tool wear rate of turning superalloy GH4169 is much faster, the cutting force increases, the tool substrate material was worn seriously. The main tool wear mechanisms are abrasive wear, adhesive wear, oxidation wear and diffusion wear. Severe abrasive wear occurred between the large amount of hard abrasive carbides in the workpiece material and the tool rake and flank faces. Ni, Fe, Cr, etc are mainly distributed in the relevant wear areas. WO3, Co3O4, Ni2O3, Fe2O3, etc indicate that oxidation wear occurred, Ni, Fe, Cr, Nb and Mo are detected across the cross-section, which means that diffusion wear has occurred.