Filtern
Erscheinungsjahr
- 2015 (22) (entfernen)
Dokumenttyp
Schlagworte
- Niobium carbide (5)
- Cobalt (4)
- Friction (3)
- NbC (3)
- Wear (3)
- Fe3Al (2)
- Hard metal (2)
- High contact pressure (2)
- Molybdenum (2)
- Oscillation (2)
Eingeladener Vortrag
- nein (11)
This paper indicates that the tribological behavior under dry sliding of a Fe3Al-niobium carbide (NbC) composite prepared by pyrometallurgical synthesis was compared to NbC-based hard metals bonded by cobalt or Fe3Al. The dry sliding wear resistance (0,1-7/10 m/s) of the present Fe3Al-NbC with ∼60% NbC was close to those known of NbC-based hard metals. No grain pull-outs or fragmentations of the NbC grains were seen in the wear tracks, as a metallurgical interphase was formed between matrix and NbC grains.
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.