Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Erscheinungsjahr
- 2018 (28) (entfernen)
Dokumenttyp
- Beitrag zu einem Tagungsband (28) (entfernen)
Sprache
- Englisch (28) (entfernen)
Schlagworte
- Niobium carbide (8)
- Wear (7)
- Friction (6)
- Hydrogen (5)
- Welding (5)
- Fe3Al (3)
- NbC (3)
- Additive Manufacturing (2)
- Cobalt (2)
- Creep-resistant steel (2)
- Hardness (2)
- Machining (2)
- Mechanical properties (2)
- Microstructure (2)
- PEEK (2)
- Residual stress (2)
- Semi-finishing (2)
- Sintering (2)
- Tribology (2)
- Turning (2)
- 316L (1)
- 9%Ni steel, (1)
- AISI 304L (1)
- Abrasion (1)
- Alumina (1)
- Aluminum (1)
- Austenitic stainless steel (1)
- Binder (1)
- CFD-model (1)
- Carbonitride (1)
- Cemented carbide (1)
- Cermet (1)
- Co (1)
- Conventional Ni-based austenitic welding electrode (1)
- Coolant-free (1)
- Crater wear (1)
- Cryogenic steel (1)
- Cryogenic temperature (1)
- Cutting tool (1)
- Cutting tools (1)
- DLC (1)
- Edge effects (1)
- FE-model (1)
- Ferritic welding electrode (1)
- Flank (1)
- Fracture toughness (1)
- Grain growth (1)
- HSLA steel (1)
- Hard metal (1)
- Hard tungsten (1)
- Hard-turning (1)
- Hardmetal (1)
- Heat treatment (1)
- High-strength steel (1)
- Hot Cracks (1)
- Hot steam (1)
- Hybrid-laser-arc welding (1)
- Hydrogen concentration (1)
- IN718 (1)
- Inserts (1)
- Interrupted milling (1)
- Iron-based alloys (1)
- LTT Weld Filler Materials (1)
- Large-scale test (1)
- Laser Metal Deposition (1)
- Laser beam welding (1)
- Laser-beam welding, (1)
- Laser-metal-deposition (1)
- Laser-plasma hybrid (1)
- Lubricated sliding (1)
- Machinability (1)
- Metal (1)
- Metal matrix composite (1)
- Neutron diffraction (1)
- Neutron imaging (1)
- Nickel (1)
- Numerical simulation (1)
- PTFE composites (1)
- Plasma-transferred-arc (1)
- Polymer composites (1)
- Post Weld Heat Treatment (PWHT) (1)
- Properties (1)
- Residual Stresses (1)
- Residual stresses (1)
- SLM printed plasma torch (1)
- SMAW (1)
- SPS (1)
- Selective Laser Melting (1)
- Selective laser melting (1)
- Solidification cracking (1)
- Solubility (1)
- Stainless Steel (1)
- Steel (1)
- Stress Relief Cracking (SRC) (1)
- Stress corrosion cracking (1)
- Temperature (1)
- Temperature behavior (1)
- Tensile strength (1)
- ToF-SIMS (1)
- Toughness (1)
- Tungsten carbide (1)
- WC (1)
- Weld pool geometry (1)
- X-ray diffraction (1)
- carrier gas hot extraction (1)
- µCT-analysis (1)
Organisationseinheit der BAM
- 9 Komponentensicherheit (28) (entfernen)
Laser Metal Deposition (LMD) as a technology for additive manufacturing allows the production of large components outside of closed working chambers. Industrial applications require a stable process as well as a constant deposition of the filler material in order to ensure uniform volume growth and reproducible mechanical properties. This paper deals with the influence of travel path strategies on temperature profile and material deposition. Meandering and spiral hatching strategies are used in the center as well as in the edge of a specimen. The temperature is measured with thermocouples attatched to the backside of the specimen. The tests are carried out on the materials S235JR and 316L. The results show a strong dependence of the maximum temperatures on the travel path strategy and the welding position on the component.
The aim of the study presented in this paper is to highlight the potential of niobium carbide cutting tool inserts for machining and to compare their performance to commercially available tungsten carbide inserts. In this work, a comparison between a conventional Wc-Co insert and NbC-Co inserts was carried out under hard machining conditions on specimens made of 100Cr6 bearing steel grade (SAE 52100).
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.
The tribological characteristics of pure and graphite filled polymers were investigated in gaseous hydrogen at ambient temperatures and in LH2 at -253°C. It could be shown that the tribological properties of PI and PEEK materials is related to the formation of a transfer film. The influence of both hydrogen and cryogenic temperatures will be discussed in the presentation.
In a first test series, the friction and wear properties of 6 polymeric candidate materials for application in LNG tribosystems were tested. The most favorable properties showed PTFE composite, filled with carbon fibers and PEEK, which showed low and stable friction and a wear coefficient in the order of 10-7 mm3N-1m-1. PTFE containing PEEK composites seem to be also appropriate for LNG applications. Admixtures of graphite as solid lubricant result in lower wear. Contrary, a lubricating mechanism of MoS2 was not observed. The PI-materials showed comparatively high friction and medium wear.
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.