Ceramic Nanomaterials for High Temperature Applications

Abstract

One of the most studied applications is the use of ceramic nanoparticles as pigments to enhance the material properties and products life-cycle. This application is more focused to polymers. The idea is a mitigation of the polymer degradation that can be observed when exposed to ultraviolet light. It has been observed that with the proper blending and binder's ratio, the mechanical and elevated temperature properties can be improved. Ceramic pigments have shown to be a good option in the nano-level for high quality coatings. As reported by Sankar S et al. [1] ceramic pigments show good impact-resistance for ferrous metals and its application in corrosive environments as well as high temperature applications based in the thermal behavior of the coating.One of the most important applications for this nano-materials, it's the direct application to aggressive environments or high temperature applications like nozzle tips for the inside combustion parts in the automotive industry or its use in turbomachinery, more specific, in combustion and hot gas path components of aviation engines or heavy duty gas turbines for the power business. For being able to apply this technology, it is important to consider the adhesion into the metal substrate of the ceramic coating, where spallation, cracking or not-homogeneous distribution can be observed when improperly added together.As reported by Vert R et al.[2] air plasma spraying technique was used for making a thin film of few micrometers thick, where it was confirmed by Vickers indentation and tensile tests, the compatibility of these two different materials (metal substrate with a ceramic coating). Processing MethodsThere are several processing methods that will be briefly discussed in this section, some of this are in experimental phase as nano-powder infiltrated transient eutectic phase (NITE) process, sol-gel method and carbon nanotubes. As reported by Kuznetsov NT [3], NITE based in the use of silicon carbide nano-powders and its mixture of yttrium and aluminum oxides to be subjected to a temperature of 1800-1950 °C at a pressure of 15-20MPA (usually referred as hot pressing) so that the melted film favors the orientation and a good matrix control of the nanoparticles.With NITE method, good mechanical characteristics are exhibited along with stress limit of 400MPA and an elasticity modulus of 310GPA with good oxidation resistance. Figure 1 shows a cross section of SiC/SiC NITE micrograph, composite material suitable for high temperature applications. It can be clearly distinguished the fiber from the matrix and its interaction.Sankar et al. [3], was a silicone resin binder developed by high temperature ceramic pigment nanoparticles with a high hardness that can be used under high temperature or aggressive environment applications. The preparation of the ceramic pigments was through Ceramic Nanomaterials for High Temperature ApplicationsCopyright © All rights are reserved by Mikhail Gamero. AbstractCeramic nanomaterials have exhibited extraordinary characteristics, based...