Lightweight porous Al ₂ O ₃ ‐based ceramics with highly controllable performance via binder jetting

Abstract This study introduces a feasible approach for preparing Al 2 O 3 ‐based ceramics with highly controllable performance via binder jetting. The Al 2 O 3 ‐based ceramics were prepared using Al 2 O 3 and H 3 BO 3 as raw materials. The results showed that the samples prepared with 0.24 mol H 3 BO 3 exhibited high apparent porosity (64%–66.67%), well‐bending strength (3.46–8.53 MPa), and low thermal conductivity (0.113–0.329 W·m −1 ·k −1 at 200–800°C). It was observed by an electron microscope that the increase of boric acid content led to the in‐situ formation of more aluminum borate grains in the sample. Meanwhile, the remaining Al 2 O 3 reacts with silicon oxide in the impregnation solution to form mullite whiskers. The whiskers ensured that the sample had superior mechanical properties and lower thermal conductivities. Based on the above properties, the possibility of Al 2 O 3 ‐based ceramics application in the aerospace field can be speculated.