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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.
Research and development of WC grades is 90 years ahead of niobium carbide-based hard materials, which showed already as light-weight and unexplored material a very high potential for many technical applications, especially for wear protection and machining. NbC evoluted recently from lab scale to pilot scale, especially in areas where established WC-based materials are causing economic, environmental or technical concerns. Benchmark trials of NbC-based hard metals indicated already a favorable performance in machining of steel components.
Metallurgy and Tribology offer different novel tools for meeting fuel economy targets.
Each of metallurgy, coatings, additives and base oils promote itself as exclusively blessed way to assure fuel economy. It is likely, that two, three or all generate the bigger fuel economy benefits and make the team working difficult for the OEM.
Metallurgy and Tribology enables the implementation of new technologies for waste heat recovery, like hot steam.
In consequence, multi-disciplinary co-engineering needs to be established. Finally, this is the most promising way, but people dislike changes.
Embargo and dual use regulations limits the global availability of thin films and also some alternative steels.
The present paper illuminates the metallurgical progress on niobium carbide based hard metal developments, which are characterized by: a.) the substitution of cobalt binder by nickel, b.) the change from SPS to conventional sintering and c.) by switching from lab to pilot scale. The toughness was increased in the frame of these developments without loosening the hardness level. The hardness-toughness profile of NbC grades match those of WC and cermet grades. Apart from the aforementioned parameters, the properties depend from the powder processing and sintering conditions.
The functional profile of nickel and NiMo bonded NbC versus cobalt bondedWC grades bonded by cobalt and nickel are benchmarked under dry sliding wear (T= 22/400°C; v= 0,1-10 m/s), abrasive wear (G65) and under dry turning and dry milling against different work piece alloys (C45E, 42CrMo4, 300WA, GG35, AlSi9Cu4Mg). The different elements explaining the wear resistance of NbC over WC will be illuminated.