Preparation of pore-controllable zirconium carbide ceramics with tunable mechanical strength, thermal conductivity and sound absorption coefficient

摘要

Porous ZrC ceramics with uniform pore distribution were successfully prepared using evaporating solvent and hot-pressing sintering. A sintering model of porous ZrC ceramics was established under applied sintering pressure to illustrate the formation mechanism of controllable pore. As the sintering pressure increases, the porosity of porous ZrC ceramics decreases from 73.5% to 55.4%, and the corresponding compressive strengths increase from 5.67 MPa to 31.25 MPa and the thermal conductivities decrease at different temperature. Sound absorption measurement shows that as the median pore sizes of porous ZrC ceramics decrease from 12.48 mu m to 4.83 mu m, their optimum sound absorption frequency shifts from 2.7 kHz to 4.5 kHz, which is attributed to the fact that porous ceramics with different pore sizes have different responses to specific frequency bands.