Process development and characterisation of UHTC matrix based on ZrB2

Kurzfassung

The project will involve the process development and characterisation of an ultra-high temperature ceramic (UHTC) matrix based on ZrB2. This UHTC could be used on ultra-high temperature surfaces such as leading edges of hypersonic vehicles or components in fusion reactors. ZrB2 is a suitable UHTC due to its high melting temperature (3245°C) as well as good properties at high temperatures. The project will include the fabrication of the porous preforms with boron powder and SiC fibres, the melt infiltration of the Zr into the preforms, scanning electron microscopy and x-ray diffraction analysis, and the mechanical and oxidation tests on various samples. The boron powder will be applied onto the fibres through two solutions; a mixture of alcohol and phenolic resin, and a polycarbosilane precursor. Melt infiltration is the chosen method of creating the UHTC due to the low cost, fast infiltration and proven success of silicon liquid infiltration of C/C-SiC. The mechanical testing will be performed by a three point bending test. Preliminary oxidation tests, in stagnating air, will take place to determine the influence of SiC and ZrC content on the oxidation behaviour. The project will contribute to the development and implementation of a new UHTC matrix that will allow higher operating temperatures of hypersonic vehicles and fusion reactors.