Aligned continuous cylindrical pores derived from electrospun polymer fibers in titanium diboride.

The use of electrospun polystyrene (PS) fibers to create continuous long range ordered multi‐scale porous structures in titanium diboride (TiB2) is investigated in this work. The introduction of electrospun PS fibers as a sacrificial filler into a colloidal suspension of TiB2 allows for easy control over the pore size, porosity, and long range ordering of the porous structures of the sintered ceramics. Green bodies were formed by vacuum infiltrating an electrospun‐fiber‐filled mold with the colloidal TiB2 suspension. The size, volume, distribution, and dispersion of the pores were optimized by carefully selecting the sacrificial polymer, the fiber diameter, the solvent, and the solid content of TiB2. The green bodies were partially sintered at 2000°C to form a multi‐scale porous structure via the removal of the PS fibers. Aligned continuous cylindrical pores homogeneously distributed across the samples were derived from the PS fibers in a range of ~5‐20 μm and partial sintering produced inter‐particle porosity with sizes of ~0.3‐1 μm. TiB2 near‐net‐shaped parts with the multi‐scale porosities (~50‐70%) were successfully cast and sintered. This low‐cost processing technique can be used in the production of thermally and mechanically anisotropic structures into near‐net shape parts, for extreme environment applications, such as high temperature insulation. [ABSTRACT FROM AUTHOR]