Controllable preparation of porous ZrB2-SiC ceramics via using KCl space holders

In this work, a novel and facile technique based on using KCl as space holders, along with partial sintering (at 1900 degrees C for 30 min), was explored to prepare porous ZrB2-SiC ceramics with controllable pore structure, tunable compressive strength and thermal conductivity. The as-prepared porous ZrB2-SiC samples possess high porosity of 45-67%, low average pore size of 3-7 mu m, high compressive strength of 32-106 MPa, and low room temperature thermal conductivity of 13-34 W m-1 K-1. The porosity, pore structure, compressive strength and thermal conductivity of porous ZrB2-SiC ceramics can be tuned simply by changing KCl content and its particle size. The effect of porosity and pore structure on the thermal conductivity of as-prepared porous ZrB2-SiC ceramics was examined and found to be consistent with the classical model for porous materials. The poring mechanism of porous ZrB2-SiC samples via adding pore-forming agent combined with partial sintering was also preliminary illustrated.

Automated summary

A novel and facile technique using KCl as space holders, combined with partial sintering, was explored to prepare porous ZrB2-SiC ceramics with controllable pore structure, tunable compressive strength, and thermal conductivity. The properties of the porous ceramics, such as porosity, pore structure, compressive strength, and thermal conductivity, can be tuned by adjusting the KCl content and particle size.