UHTC composites application

RMI is applicable for preparing C/UHTC composite. In RMI, liquid metal melt penetrates into a porous C/C preform under an inert atmosphere or a vacuum condition. The metal melt expands to fill the pores, ultimately resulting in a dense... 

Having looked into and critically analyzed some of the processing issues, property requirements and more recently developed advanced composites based on the ultra-high temperature ceramics, in this section we summarize the various applications (current and potential) of these material classes. As has been emphasized in the preceding sections, UHTCs are nsed for applications that demand withstanding temperatures above 2000°C, along with harsh atmospheric conditions. Such conditions are typically enconntered dnring the re-entry of space shuttles into the atmosphere. Hence, a lot of research on UHTCs has been conducted with such applications in mind. 

Emerging potential applications for UHTCs require complex shapes and/or functionalized surfaces. In this chapter, recent achievements in the development of monolithic and composites based on Hf and Zr borides and carbides are presented and discussed, especially with reference to the effects of shaping and sintering technologies. Novel UHTC structures and architectures, dense and porous, open new potential fields of applications for UHTCs not only in aerospace applications, but also in energy sectors (such as solar energy), hot gases and molten metal filtration and catalysis. 

In the following sections, practical examples of application of the possibilities offered by wet forming techniques to produce UHTC components are presented. A systematic study of ZrB2-4 vol% SijN and ZrB2-20 vol% SiC-4 vol% SijN compositions, conducted by the authors to produce complex shape devices by various wet-forming techniques and PLS, is reported. Beside, ZrB with no sintering aid is also proposed. 

In summary, RMI is a promising fabrication route for ultra high temperature ceramic matrix composite. Further efforts should be made to perfect the RMI process. It is believed that RMI can emerge as a low cost process to provide high performance C/UHTC components for ultra high temperature applications in the future. 

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