TY - CONF A1 - Genga, R. M. A1 - Glaser, D. A1 - Rokebrand, P. A1 - Cornish, L. A. A1 - Woydt, M. A1 - Gradt, Thomas A1 - Janse van Vuuren, A. A1 - Polese, C. ED - von Leipzig, K. ED - Sacks, N. ED - McClelland, M. T1 - Laser shock peening: A NbC based cermet enhancement alternative for improved GCI interrupted face-milling N2 - Attempts were made to improve the properties and machining performance of NbC based cermet cutting inserts for face milling of grey cast iron (GCI) (BS 1452/GG35) by spark plasma sintering (SPS), use of sub-stoichiometric NbC (NbC₀ˏ₈₈), Cr₃C₂ and Mo₂C additives and laser shock peening (LSP). The microstructure, hardness, fracture toughness and Young’s modulus of WC–Co, NbC₀ˏ₈₈-Co and NbC₀ˏ₈₈-Ni cermet-based inserts were investigated for machining performance. Additions of Mo₂C and manufacture by SPS significantly refined the NbC₀ˏ₈₈-Ni/Co cermet’s carbide grain size from ~5.0 μm to <0.9 μm, which increased the hardness (by ~4GPa) and wear resistance. Laser shock peening (LSP) improved the fracture toughness of all the inserts, from 10% (in the SPS WC based in cermets) to ~100% (in the LPS NbC based cermets). Uncoated cutting inserts were manufactured from the sintered cermets in an SNMA (double sided square insert without a chipformer on the cutting edge) shape (12.7 × 12.7 × 4.3 mm³, 1.6 mm nose radius). The inserts were used for interrupted face-milling of GCI at cutting speeds (ν˛) ranging from 100 m/minute (400 rpm)–500 m/minute (2000 rpm) and depths of cut (ɑₚ) of 0.2–1.0 mm. The insert wear was measured after every pass and analyzed by annular dark field scanning transmission electron microscopy (ADF-STEM). Cutting temperatures were measured with a high-speed thermal camera and forces were measured using a Kistler dynamometer. During machining at ν˛ = 200 m/minute and ɑₚ = 1.0 mm, WC–Co inserts had the lowest flank wear rate (FWR), although LSP significantly improved the tool life of the NbC₀ˏ₈₈-Ni inserts, significantly reducing the FWR from 148.63 μm/minute to 99.79 μm/minute (by ~33%) and the average resultant force from 1257 ± 15 N to 535 ± 15 N. During machining at ν˛ = 500 m/minute and ɑₚ = 0.2 mm, LSP significantly lowered the FWRs of the NbC₀ˏ₈₈ inserts, giving better tool life than all the WC based inserts. Generally, LSP improved the NbC₀ˏ₈₈ inserts’ tool life, reducing the flank wear rate by up to 33% during roughing and 63% during finishing. T2 - 8th International Conference on Competitive Manufacturing (COMA ’22) CY - Stellenbosch, South Africa DA - 09.03.2022 KW - Niobium carbide KW - Laser shock peening KW - Face milling KW - Tool wear PY - 2023 SN - 978-3-031-15602-1 SN - 978-3-031-15601-4 SN - 978-3-031-15604-5 DO - https://doi.org/10.1007/978-3-031-15602-1_62 SN - 2194-0525 SN - 2194-0533 N1 - Serientitel: Lecture notes in production engineering – Series title: Lecture notes in production engineering SP - 871 EP - 889 PB - Springer CY - Cham AN - OPUS4-62689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Minimization of tool wear in milling of iron aluminides using ultrasonic-assisted process N2 - Presentation of key results from the ZIM cooperation project "TEWUFEAL" on tool development for ultrasonic-assisted milling of iron aluminide alloys cast in gravity die casting. T2 - 24th International Conference on Wear of Materials CY - Banff, Canada DA - 16.04.2023 KW - Iron aluminides KW - Ultrasonic-assisted milling KW - Surface integrity KW - Tool wear PY - 2023 AN - OPUS4-59259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Wear behavior of innovative niobium carbide cutting tools in ultrasonic-assisted finishing milling N2 - The resources of niobium exceed the ones of tungsten by an order of magnitude. With 92%, Brazil is today the main global producer of niobium. Hence, niobium carbides (NbC) are a sustainable and economic alternative to conventionally used cutting materials, especially tungsten carbides (WC). Moreover, NbC can be used in Ni alloy matrix and thus offer significant advantages by substituting WC in Co matrix as cutting materials in terms of health risks and raw material price and supply risk. Based on recent studies which found an increased performance of NbC compared to WC cutting tools in machining higher strength steels, the composition NbC12Ni4Mo4VC was chosen for finish machining of a high-strength steel S960QL in this study. The experiments were carried out on an ultrasonic-assisted 5-axis milling machine using NbC tools specially made to benchmark them with commercially available coated WC cutting inserts. In addition, the influence of a coating system for the NbC inserts is tested and evaluated for its performance in the cutting process. Tool wear and cutting force analyses are implied to identify optimal parameter combinations as well as tool properties for the novel NbC tool. Together with the oscillation of ultrasonic-assisted milling, the loads on the component surface and the tool can be reduced and the wear behavior of the novel NbC tool can be refined. These milling tests are accompanied by standardized wear tests, i.e., pin-on-disc, between the aforementioned material combinations, and the results are correlated with each other. Finally, the behavior when using hard-to-cut materials such as Ni alloys, or innovative materials such as iron aluminide is also being tested, as these are constantly in the focus of machining optimization. With this strategy, comprehensive knowledge is achievable for future efficient application of NbC for milling tools, which have already been researched for decades using WC. T2 - 24th International Conference on Wear of Materials CY - Banff, Canada DA - 16.04.2023 KW - Cutting tool KW - Niobium carbide KW - Tool wear KW - Ultrasonic-assisted milling PY - 2023 AN - OPUS4-59258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Giese, Marcel T1 - Alloy modification and ultrasonic assisted milling of wear resistant alloys with defined surfaces N2 - The targets for reducing CO2 emissions are closely linked to the development of highly efficient and economical steel components in plant, process and power plant technology, which require wear protection coatings tailored to the application and steel material for high combined corrosive, tribological, thermal and mechanical stresses. In addition to increasing demands to replace conventional cobalt alloys with nickel alloys as a result of price and supply risks, there is a growing demand in industry for defined functional surfaces of high quality for these coatings. Milling is a standard process for finish machining. The desired properties of wear resistant alloys imply significant challenges for the milling process due to high tool wear and surface defects. Besides the hardness of the coating materials, especially due to the precipitations, inhomogeneous, anisotropic weld structures of the claddings lead to further deteriorations of milling processes due to unstable milling conditions and process forces. A joint project of BAM and ISAF of TU Clausthal (Fosta P1550/IGF 21959 N) investigates the optimization of these challenging machining conditions by means of alloy modifications of the welding powder for plasma transferred arc cladding, without reducing the wear protection potential and using ultrasonic assisted milling process. In this paper, the influence of the microstructure and precipitation morphology adjusted by means of alloy modification on machining is investigated. The alloy used is a NiCrMoSiFeB alloy (trade name: Colmonoy 56 PTA). Through metallurgical investigations and in-situ measurement of cutting forces and temperatures at the cutting edge during the milling process as well as the subsequent investigation of tool wear and surface integrity, a detailed analysis and correlation between microstructural properties and machinability is feasible. The findings allow recommendations for standards and processing guidelines, enabling safe and economical production of highly stressed steel components with non-critical, cost-reduced materials. T2 - European steel technology and application days CY - Düsseldorf, Germany DA - 12.06.2023 KW - Ultrasonic assisted milling KW - Surface integrity KW - Tool wear PY - 2023 AN - OPUS4-58945 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witte, Julien A1 - Hübler, Daniela A1 - Schröpfer, Dirk A1 - Börner, Andreas A1 - Kannengießer, Thomas ED - Hanke, S. T1 - Wear behavior of innovative niobium carbide cutting tools in ultrasonic-assisted finishing milling N2 - The resources of niobium exceed the ones of tungsten by an order of magnitude. With 92%, Brazil is today the main global producer of niobium. Hence, niobium carbides (NbC) are a sustainable and economic alternative to conventionally used cutting materials, especially tungsten carbides (WC). Moreover, NbC can be used in Ni alloy matrix and thus offer significant advantages by substituting WC in Co matrix as cutting materials in terms of health risks and raw material price and supply risk. Based on recent studies which found an increased performance of NbC compared to WC cutting tools in machining higher strength steels, the composition NbC12Ni4Mo4VC was chosen for finish machining of a high-strength steel S960QL in this study. The experiments were carried out on an ultrasonic-assisted 5-axis milling machine using NbC tools specially made to benchmark them with commercially available coated WC cutting inserts. In addition, the influence of a coating system for the NbC inserts is tested and evaluated for its performance in the cutting process. Tool wear and cutting force analyses are implied to identify optimal parameter combinations as well as tool properties for the novel NbC tool. Together with the oscillation of ultrasonic-assisted milling, the loads on the component surface and the tool can be reduced and the wear behavior of the novel NbC tool can be refined. These milling tests are accompanied by standardized wear tests, i.e., pin-on-disc, between the aforementioned material combinations, and the results are correlated with each other. Finally, the behavior when using hard-to-cut materials such as Ni alloys, or innovative materials such as iron aluminide is also being tested, as these are constantly in the focus of machining optimization. With this strategy, comprehensive knowledge is achievable for future efficient application of NbC for milling tools, which have already been researched for decades using WC. T2 - 24th International Conference on Wear of Materials CY - Banff, Canada DA - 16.04.2023 KW - Niobium carbide KW - Cutting tool KW - Ultrasonic-assisted milling KW - Tool wear PY - 2023 DO - https://doi.org/10.1016/j.wear.2023.204722 SN - 0043-1648 VL - 522 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-57561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -