Testing of AlN–TiB2 Ceramics by Pulsed-Periodic Thermal Load Possible in Fusion Devices

Abstract

Experimental studies involving multiple (~10⁴ cycles) exposures of ELM-like pulses revealed key erosion patterns in AlN–TiB₂ composite ceramics. The primary degradation mechanism was found to be damage to the aluminum-containing phase, while significant erosion of refractory TiB₂ occurred only after substantial removal of the low-melting-point component consisting of free aluminum and aluminum nitride. Although the aluminum-containing phase demonstrates relatively low thermal shock resistance, it plays a crucial role by filling pores and enhancing both thermal conductivity and mechanical strength of the material. For practical implementation of TiB₂-based materials, two key challenges must be addressed: optimization of additive materials and refinement of manufacturing processes to reduce material porosity. The use of aluminum-containing materials in plasma-facing components of deuterium–tritium fusion devices may lead to accumulation of the long-lived radioactive ²⁶Al isotope. Nevertheless, the results obtained demonstrate the potential of composite materials combining refractory and low-melting-point constituents.