Temperature-dependent heat transfer deterioration in ordered graphene/ceramic composites

Abstract

Boosting heat transfer of ultrahigh temperature ceramics (UHTCs) with dimensional-crossover graphene has become an increasing challenge for improving the thermal protective performance of new-generation spacecraft. Yet its characteristics of anisotropic and high interfacial thermal resistance inevitably cause heat transfer deterioration at high temperatures. Here we develop a few ZrB₂/graphene/ZrB₂ interface-dominated diffuse models that are driven by bonding configurations and thermal converger. It has been found that forming stronger bonding configurations by Zr-C interfacial bonding and designing a preferred thermal converger by ordered graphene are both unarguable ways of suppressing high-temperature heat transfer deterioration. Each Zr-C interfacial bonding serves as an independent sluice gate to accelerate heat flow. More high-frequency phonons are excited at high temperature, which augments the interfacial thermal conductance from 38.5 to 335.4 MW·m⁻²·K⁻¹ at 700 K. Impressively, a concept of thermal converger inspires us to adopt ordered graphene for changing the diverging behavior in isotropic ZrB₂ composites. Its convergent process combines with anisotropic characteristics to transform the isotropic heat flow into the highly ordered graphene. Their thermal conductance can be regulated from minimum (2.5) to maximum (80.8 W·m⁻¹·K⁻¹) by rotating the ordered graphene from 90^° to 7.5^°. This work paves an optimal way for manipulating the heat transfer of UHTCs.