TY - CONF A1 - Wäsche, Rolf A1 - Ehrke, R. A1 - Kramer, R. A1 - Jayachandran, A. R. A1 - Brandt, G. T1 - Influence of temperature on tribological behaviour of DLC coatings under lubricated conditions up to 250°C T2 - Proceedings of Asia International Conference on Tribology N2 - In the present work it was shown that there is an influence of temperature and counter body material on the tribological properties of a-C:H coatings deposited on Cronidur 30 steel in a lubricated ball on disk contact situation. T2 - ASIATRIB 2018 CY - Kuching, Sarawak, Malaysia DA - 17.09.2018 KW - DLC KW - Temperature KW - Lubricated sliding PY - 2018 SP - 253 EP - 254 AN - OPUS4-46213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wägner, Yannick A1 - Binkowski, Sigrid A1 - Woydt, Mathias T1 - Charakterisierung von Hartstoffphasen in Gefüge T2 - Fortschritte in der Metallographie - Sonderbände der Praktischen Metallographie N2 - Der Beitrag handelt von der Verbesserung der Verschleißbeständigkeit von Hartstoffphasen in Metal Matrix Composites (MMC), Hartgusslegierungen, Hadfield-Stählen oder Werkzeugstählen. T2 - 15. International Metallographie-Tagung CY - Leoben, Asutria DA - 19.09.2018 KW - Verschleißbeständigkeit KW - Hartstoffphasen KW - NbC PY - 2018 SN - 978-3-88355-416-7 VL - 52 SP - 133 EP - 138 PB - DGM - INVENTUM GmbH CY - Sankt Augustin AN - OPUS4-46056 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Wäsche, Rolf A1 - Brandt, Guido A1 - Ehrke, Roman A1 - Yano, S. A1 - Sasaki, S. T1 - Tribology in hot steam for energy recovery T2 - Industrial and Automotive Lubrication N2 - The wear rates of self-mated alumina couples show that friction as well as wear is largely determined by the above-mentioned hydro-thermal conditions. The presence of water and its amount available in the surrounding system either in liquid or in gaseous form plays a key role for friction and wear behavior and can be beneficial for the tribological profile of steam degradation resistant materials. Hot steam enhances the tribo-chemical formations of oxides and hydroxides on MgO-ZrO2 alumina and antimony impregnated carbon. T2 - 21th International Colloquium Tribology CY - Stuttgart/Ostfildern, Germany DA - 09.01.2018 KW - Tribology KW - Friction KW - Alumina KW - Hot steam PY - 2018 SP - 1 EP - 2 AN - OPUS4-43896 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Mohrbacher, H. T1 - The tribological property profile of hard metals and metal matrix composites based on niobium carbide T2 - Proceedings of the International Symposium on Wear Resistant Alloys for the Mining and Processing Industry N2 - This work is focused on the tribological profile of NbC-based material, as well as their potential applications and environmental implications. 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 - Metal KW - Binder KW - Metal matrix composite KW - Friction KW - Wear KW - Hardness KW - Solubility KW - Toughness KW - Abrasion PY - 2018 SN - 978-0-692-05382-9 SP - 427 EP - 461 AN - OPUS4-44201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Huang, S. A1 - Vleugels, J. A1 - Mohrbacher, H. A1 - Cannizza, E. T1 - Tailoring the functional profile of niobium carbide (NbC) as cutting tool materials and for wear protection T2 - 2018 World Congress on Powder Metallurgy N2 - In the present work it was shown that the properties of NbCx, like micro-hardness, hot-hardness, sliding wear resistance, elastic modulus and toughness can be tailored by the C/Nb ratio, the addition of secondary carbides and the type of binder. T2 - WORLDPM2018 CY - Beijing, China DA - 16.09.2018 KW - Niobium carbide KW - Properties KW - Wear KW - Machining PY - 2018 SP - Part 5, 785 EP - 795 AN - OPUS4-46204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - Machining with niobium carbide based tools T2 - Reibung, Schmierung, Verschleiß N2 - The present work deals with Niobcarbid (NbC). Strategic reflections on tungsten carbide and more and more stringent toxicological restrictions for cobalt associated for both with spiraling stock market prices have attracted recently some attention for Niobium carbide as a substitute for tungsten carbide in machining. T2 - 59. Tribologie-Fachtagung CY - Goettingen, Germany DA - 24.09.2018 KW - Hard tungsten KW - Semi-finishing KW - Niobium carbide KW - Friction KW - Wear KW - NbC KW - Hard metal KW - Cobalt KW - Nickel KW - Fe3Al PY - 2018 SN - 978-3-9817451-3-9 SP - 48/1 EP - 48/11 AN - OPUS4-46170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - Dry turning with niobium carbide based tools T2 - POWDERMET 2018 N2 - Niobium carbide (NbC) has attracted recently some attention as a substitute for tungsten carbide in machining. In the present work it was shown that the metallurgical and mechanical aspects favoring long tool lifes of NbC. T2 - POWDERMET 2018 CY - San Antonio, TX, USA DA - 17.06.2018 KW - Niobium carbide KW - NbC KW - Cutting tool KW - Machining PY - 2018 SN - 978-1-943694-18-1 VL - 2 SP - 538 EP - 545 AN - OPUS4-45802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vollert, F. A1 - Dixneit, Jonny A1 - Gibmeier, J. ED - Marais, D. ED - Holden, T.M. ED - Venter, A.M. T1 - Effect of Residual Stress Relaxation due to Sample Extraction on the Detectability of Hot Crack Networks in LTT Welds by means of µCT T2 - Mechanical stress evaluation by neutron and synchrotron radiation, , MECA SENS 2017 N2 - Investigations on weldability often deal with hot cracking as one of the most prevalent failure mechanisms during weld fabrication. The modified varestraint transvarestraint hot cracking test (MVT) is well known to assess the hot cracking susceptibility of materials. The shortcoming of this approach is that the information is only from the very near surface region which inhibits access to the characteristic of the hot crack network in the bulk. Here, we report about an alternative approach to monitor the entire 3D hot crack network after welding by means of microfocus X-ray computer tomography (µCT). However, to provide sufficient high spatial resolution small samples must be sectioned from the MVT-welded joint. The sampling is accompanied by local relaxation of the residual stress distributions that are induced by welding, which can have an impact on the crack volumes prior to the sampling. The studies were carried out to investigate the hot cracking susceptibility of low transformation temperature filler materials (LTT). As high compression residual stresses up to -600 MPa in the area of the crack networks were determined by means of the contour method, stress relaxation caused by sectioning for µCT sample extraction can affect the detectability of the cracks later on. X-ray diffraction studies revealed surface residual stress relaxations up to about 400 MPa due to cutting. To investigate this effect, the specimens with hot cracks were subjected to a load test with known stress states. The results clearly show that local stress relaxations will have a strong impact on the volume images reconstructed from tomography analysis. This effect must be considered during hot crack assessment on basis of µCT data. T2 - 9th International Conference on Mechanical Stress Evaluation by Neutron and Synchrotron Radiation (MECA SENS 2017) CY - Skukuza Rest Camp, South Africa DA - 19.09.2017 KW - LTT Weld Filler Materials KW - µCT-analysis KW - Hot Cracks KW - Welding PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-456765 SN - 978-1-945291-66-1 DO - https://doi.org/10.21741/9781945291678-13 SN - 2474-395X VL - 4 SP - 85 EP - 90 AN - OPUS4-45676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Uhlmann, E. A1 - Meier, P. A1 - Hinzmann, D. A1 - Kropidlowski, K. A1 - Prasol, L. A1 - Woydt, Mathias T1 - Dry turning with niobium carbide based tools T2 - 2018 World Congress on Powder Metallurgy N2 - In the present work it was shown that Niobium carbide (NbC) offers a competitive profile compared to tungsten carbide (WC) as cutting material regarding ist wear resistance preferably in metal cutting processes. T2 - WORLDPM 2018 CY - Beijing, China DA - 16.09.2018 KW - Turning KW - Semi-finishing KW - Niobium carbide KW - Tungsten carbide KW - Iron-based alloys KW - Aluminum PY - 2018 SP - Part 5, 775 EP - 784 AN - OPUS4-46203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiede, Tobias A1 - Cabeza, Sandra A1 - Mishurova, Tatiana A1 - Nadammal, Naresh A1 - Kromm, Arne A1 - Bode, Johannes A1 - Haberland, C. A1 - Bruno, Giovanni T1 - An assessment of bulk residual stress in selective laser melted Inconel 718 T2 - Proceedings ECNDT2018 N2 - Additive Manufacturing (AM) of metals has become industrially viable for a large variety of applications, including aerospace, automotive and medicine. Powder bed techniques such as Selective Laser Melting (SLM) based on layer-by-layer deposition and laser melt enable numerous degrees of freedom for the geometrical design. Developing during the manufacturing process, residual stresses may limit the application of SLM parts by reducing the load bearing capacity as well as induce unwanted distortion depending on the boundary conditions specified in manufacturing. The residual stress distribution in the bulk of IN718 elongated prisms produced by SLM was studied non-destructively by means of neutron diffraction. The samples with different scanning strategies, i.e. hatching length, were measured in as-build condition (on a build plate) and after removal from the build plate. The absolute values of all stress components decreased after removal from the build plate. Together with surface scan utilizing a coordinate-measuring machine (CMM), it is possible to link the stress release to the sample distortion. Obtained results indicated different residual stress states for each of the transversal, longitudinal and normal component depending on the thermal gradient in the respective direction. T2 - ECNDT 2018 CY - Göteborg, Sweden DA - 11.06.2018 KW - Residual stress KW - Selective laser melting KW - Neutron diffraction KW - IN718 PY - 2018 UR - http://cdn.ecndt2018.com/wp-content/uploads/2018/05/ecndt-0315-2018-File001.pdf SP - 1 AN - OPUS4-45325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -