Cermets composition

Non-metallic Materials Carbides, carbon, ceramic fiber, ceramic, cermet, composite, cork, elastomer, felt, fiber, glass, glycerin, non-metallic bearing material, rubber (natural), rubber (synthetic), silicone, wood, leather. 

WC-free cermet compositions such as TiC-Mo2C-Ni and TiC-VC-Ni-Fe-Co were synthesized in the 1930s for metalcutting applications. However, these alloys could not compete with the stronger WC-Co cutting tools. Improvements in tool performance were obtained in the 1950s with the additions of other carbides such as tantalum carbides (TaC) and niobium carbides (NbC) to the TiC-Mo-Ni alloys. 

In order to overcome the problems with pure metallic anodes, ceramic-metal (cermet) composite anode concepts have been... 

Figure 95. Isothermal section of the Fe-Ti-B system at 1000°C. The point indicates the cermet composition and the arrow the change in composition if the titanium content in the liquid phase is...

The usual anode is a cermet (composite material made of a ceramic and a metal). Porous Ni-YSZ (yttria-stabilised zirconia) is the state-of-the-art electrode, presenting electronic and ionic conductivities in order to increase the number of reaction sites, called triple phase boundaries. It corresponds to the area where 0 , e and H2 are all present for the time required for the oxidation reaction to occur. No single phase has been found to completely fit all the requirements for an anode thermal and chemical compatibilities with the electrolyte, mixed ionic and electronic conductivity, high electro-catalytic activity and stability in reductive atmosphere. 

Table 49. Recommended preparation of a ceramic/cermet composite...

Figure 110. Ceramic/cermet composite from a high-temperature fuel cell. The section has been subjected to contrast enhancement, BF. The composite was produced by slip casting and a coat mix process. P = perovskite Lao,84Sro,i6Mn03 YSZ = Y203-stabilized zirconium oxide.

CaZro.gYo.iOs-fi cermet composite membranes. Sep. Purif. TechnoL, 79,... 

Ceramies are commonly used in conjnnction with metals to form composites for electronic appheations, especially thermal management. Ceramic-metal (cermet) composites typically have a lower temperature coefficient of expansion (TCE) than metals, a higher... 

The limiting factor for fuel cell performance is often the extent of triple phase boundary (TPB) available to be the site of cathode or anode reactions. Whilst the properties of the materials used, whether cermet, composite oxides or a mixed ion... 

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