TY - JOUR A1 - Huang, S.G. A1 - Vanmeensel, K. A1 - Mohrbacher, H. A1 - Woydt, Mathias A1 - Vleugels, J. T1 - Microstructure and mechanical porperties of NbC-matrix hardmetals with secondary carbide addition and different metal binders N2 - NbC has a relatively high hardness (19.6 GPa) and melting temperature (3600 °C) and is usually applied as a grain growth inhibitor in WC–Co hardmetals. The current study reports on the influence of the sintering technology and overall chemical composition on the microstructure and mechanical properties of NbC-based hardmetals, using Co as a binder. The partial replacement of NbC by 5 wt.% WC, Mo2C, VC or TiC allows one to significantly improve the hardness and toughness of the NbC–Co materials. The influence of different binders, i.e., Co, 316L stainless steel and Fe3Al on the microstructure and mechanical properties of NbC-based hardmetals was also investigated. The powder mixtures were sintered in the solid state by PECS and liquid state by conventional vacuum sintering. Detailed microstructural analysis was conducted by EPMA elemental mapping and WDS point analysis. Mechanical properties, including Vickers hardness and indentation toughness were assessed. KW - Niobium carbide KW - Sintering KW - Grain growth KW - Microstructure KW - Mechanical properties PY - 2015 U6 - https://doi.org/10.1016/j.ijrmhm.2014.10.014 SN - 0263-4368 SN - 0958-0611 VL - 48 SP - 418 EP - 426 PB - Elsevier AN - OPUS4-31974 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - Influence of VC and Mo2C on the microstructure and mechanical properties of Ni bonded NbC-cermets N2 - The current study reports on the effect of VC and Mo2C carbides on the microstructure and mechanical properties of Ni bonded NbC cermets. T2 - World PM2016 CY - Hamburg, Germany DA - 09.10.2016 KW - Niobium carbide KW - NbC KW - Liquid phase sintering (LPS) KW - Hard materials PY - 2016 SN - ISBN 978-1-899072-47-7 SP - 1 EP - 7 AN - OPUS4-37891 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - NbC-based cermets: influence of secondary carbide addition and metal binder N2 - Full densification of Fe, Co and Ni bonded NbC based cermet’s was achieved by pressure less liquid phase sintering in vacuum for one hour at 1420°C. The hardness and toughness of the NbC matrix cermet’s can be mainly tailored by the binder composition and secondary carbide additions. Ni binder based NbC cermet’s allow the combination of high hardness and improved toughness. The addition of lesser amounts of VC/Cr3C2 in a NbC partially substituted WC-Co cemented carbide increased significantly the hardness in combination with a moderate fracture toughness. T2 - International Symposium on Wear Resistant Alloys for the Mining and Processing Industry CY - Sao Paulo, Brazil DA - 04.05.2015 KW - Niobium carbide KW - Hardmetal KW - Cemented carbide KW - Sintering KW - Grain growth KW - Microstructure KW - Hardness KW - Fracture toughness PY - 2018 SN - 978-0-692-05382-9 SP - 521 EP - 534 AN - OPUS4-44206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - Effect of Ti(C0.7N0.3) content on the microstructure and mechanical properties of Ni bonded NbC-Ti(C0.7N0.3) based cermets N2 - In the present work it was shown that the addition of VC or a combination of VC + Ti(C0.7N0.3) was efficient in reducing the NbC grain growth during liquid phase sintering, when compared to NbC-Ni equivalents. A finest NbC grain size of 1.48 µm was obtained in the NbC-15 Ti(C0.7N0.3)-10 Ni-7.5 VC cermet, exhibiting a hardness of 1486 +/- 7 kg/mm2 and a fracture toughness of 8.7 +/- 0.1 MPa m 1/2. KW - Cermet KW - Niobium carbide KW - Carbonitride KW - Sintering KW - Mechanical properties PY - 2018 U6 - https://doi.org/10.4028/www.scientific.net/SSP.274.43 SN - 1662-9779 VL - 274 SP - 43 EP - 52 PB - Trans Tech Publ. CY - Uetikon AN - OPUS4-44962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - Microstructure and mechanical properties of NbC matrix cermets using Ni containing metal binder N2 - The current study reports on the effect of the addition of Al metal and secondary refractory carbides on the microstructure and mechanical properties of Ni bonded NbC matrix cermets. KW - NbC KW - Niobium carbide KW - Hardness KW - Hard materials PY - 2016 U6 - https://doi.org/10.1016/j.mprp.2016.05.009 VL - 71 IS - 5 SP - 349 EP - 355 PB - Elsevier Ltd. AN - OPUS4-44623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - Densification and tribological profile of niobium oxide N2 - The origin of the intrinsic wear resistance of NbC-based materials is investigated through an assessment of the tribological performance of fully dense, crack-free spark plasma sintered Nb2O5 (here as a reduced polymorph: monoclinic Nb12O29 or NbO2.416). The most likely wear mechanism on NbC is the tribo-oxidation to Nb2O5. The unlubricated (dry) friction and wear behavior of alumina (99.7%) mated against rotating disks of crack-free niobium(V)oxide (Nb2O5) under unidirectional sliding (0.03–10m/s; 22°C and 400°C) and oscillation (f=20 Hz, dx=200 mm, 2/50/98% rel. humidity, n=105/106 cycles) will be presented. The microstructure and mechanical properties of the crack-free Nb2O5 are assessed. The tribological data obtained are benchmarked with different NbC grades, ceramics, cermets and thermally sprayed coatings. KW - Friction KW - Wear KW - Nb2O5 KW - Nb12O29 KW - Niobium oxide KW - Strength KW - Modulus KW - High temperatures PY - 2016 U6 - https://doi.org/10.1016/j.wear.2016.02.003 SN - 0043-1648 VL - 352-353 SP - 65 EP - 71 PB - Elsevier B.V. AN - OPUS4-35805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - NbC grain growth control and mechanical properties of Ni bonded NbC cermets prepared by vacuum liquid phase sintering N2 - The current study reports on the effect of the sintering temperature and secondary carbide (VC, Mo2C and TiC) and Mo additions on the NbC grain growth, microstructure evolution as well as concomitant Vickers hardness (HV30) and fracture toughness of Ni-bonded NbC cermets. KW - Cermet KW - Niobium carbide KW - Sintering KW - Microstructure KW - Mechanical properties PY - 2018 U6 - https://doi.org/10.1016/j.ijrmhm.2017.12.013 SN - 0263-4368 VL - 72 SP - 63 EP - 70 PB - Elsevier Science CY - Amsterdam AN - OPUS4-43582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - Microstructure and tribological performance of NbC-Ni cermets modified by VC and Mo2C N2 - The current study reports on the influence of the Addition of 5–15 vol% VC or/and Mo2C carbide on the microstructure and mechanical properties of nickel bonded NbC cermets, which are compared to cobalt bonded NbC cermets. The NbC, Ni and secondary carbides powder mixtures were liquid phase sintered for 1 h at 1420 °C in vacuum. The fully densified cermets are composed of a cubic NbC grains matrix and an evenly distributed fcc Ni binder. NbC grain growth was significantly inhibited and a homogeneous NbC grain size distribution was obtained in the cermets with VC/Mo2C additions. The mechanical properties of the NbC-Ni matrix cermets are strongly dependent on the carbide and Ni binder content and are directly compared to their NbC-Co equivalents. The liquid phase sintered NbC-12 vol% Ni cermet had a modest Vickers hardness (HV30) of 1077 ± 22 kg/mm2 and an indentation toughness of 9.1 ± 0.5 MPa·m1/2. With the addition of 10–15 vol% VC, the hardness increased to 1359 ± 15 kg/mm2, whereas the toughness increased to 11.3 ± 0.1 MPa·m1/2. Addition of 5 and 10 vol% Mo2C into a NbC-12 vol% Ni mixtures generated the same values in HV30 and KIC when compared to VC additions. A maximum flexural strength of 1899 ± 77 MPa was obtained in the cermet with 20 vol% Ni binder and 4 vol% VC+4 vol% Mo2C addition, exhibiting a high fracture toughness of 15.0 ± 0.5 MPa·m1/2, but associated with a loss in hardness due to the high Ni content. The dry sliding wear behaviour was established at room temperature and 400 °C from 0.1 to 10 m/s. KW - Cermet KW - Liquid phase sintering KW - Grain growth KW - Wear KW - Niobium carbide PY - 2017 U6 - https://doi.org/10.1016/j.ijrmhm.2017.03.012 SN - 0263-4368 VL - 66 SP - 188 EP - 197 AN - OPUS4-40505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - Effect of carbon content on the microstructure and mechanical properties of NbC-Ni based cermets N2 - The aim of this work was to correlate the carbon content in NbC-Ni starting powders with the resulting microstructure, hardness and fracture toughness of Ni-bonded NbC cermets. T2 - 19. Plansee Seminar CY - Reutte, Austria DA - 29.05.2017 KW - Cermet KW - Liquid phase sintering KW - Microstructure KW - Hardness KW - Carbon PY - 2017 AN - OPUS4-40647 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - NbC grain growth control and mechanical properties of Ni bonded NbC cermets prepared by vacuum liquid phase sintering N2 - The current study reports on the effect of the sintering temperature and secondary carbide (VC, Mo2C and TiC) additions on the microstructure and concommitant Vickers hardness (HV30) and fracture toughness of Ni-bonded NbC cermets. All cermets were prepared by pressureless sintering in vacuum. Detailed microstructural investigation was performed by electron probe microanalysis (EPMA) and X-ray diffraction (XRD) analysis. Sintering results indicated that both the sintering temperature and secondary carbide additions had a significant effect on the properties of NbC-Ni cermets. Nickel pools and residual pores were observed in the cermets sintered at temperatures ≤ 1340 °C. Increasing of the sintering temperature up to 1420 or 1480 °C resulted in fully densified NbC-Ni based cermets composed of homogeneous contrast cubic NbC grains for the single carbide (VC or Mo2C) modyfied system, whereas core-rim structured NbC grains were observed with the additon of TiC + VC or TiC+Mo2C. The secondary carbide doped cermets with 5–10 vol.% VC/Mo2C and 10 vol.% TiC showed a significantly improved hardness and fracture toughness, as compared to the plain NbC-Ni cermets. T2 - 19. Plansee Seminar CY - Reutte, Austria DA - 29.05.2017 KW - Cermet KW - Hard materials KW - Sintering KW - Microstructure KW - Core-rim KW - Mechanical properties PY - 2017 SP - HM 13/1 EP - HM 13/11 AN - OPUS4-40592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huang, S. G. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Woydt, Mathias T1 - Effect of carbon content on the microstructure and mechanical properties of NbC-Ni based cermets N2 - The aim of this work was to correlate the carbon content in NbC-Ni starting powders with the resulting microstructure, hardness and fracture toughness of Ni-bonded NbC cermets. T2 - 19. Plansee Seminar CY - Reutte, Austria DA - 29.05.2017 KW - Cermet KW - Liquid phase sintering KW - Microstructure KW - Hardness KW - Carbon PY - 2017 SP - HM 109/1 EP - HM 109/11 AN - OPUS4-40595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -