LAUSR

Abstract In this contribution, a manageable foam-casting technique for the preparation of novel aluminum borate foams (ABFs) as thermal insulators with highly controllable performances is presented. ABFs were fabricated from α-Al2O3 and 2Al2O3·B2O3 with the addition of various amounts of foaming agents, thickening agents, and slurry solid contents. The dispersions and rheological properties of the slurries were then examined, followed by exploration of microstructural evolution and testing of mechanical/thermal properties. It should be noted that the generated micro-pores generated and interlocking rod-like 9Al2O3·2B2O3 crystals may lead to superior mechanical tolerances and lower thermal conductivities for the ABFs. In general, the as-prepared ABFs with porosities ranging from 73.8 to 96.3 vol%, compressive strengths of 8.20–0.15 MPa, and thermal conductivities of 0.228–0.046 W/(mK) (200–800 °C) could render them suitable for application as high-temperature thermal insulating materials.