A novel route for the fabrication of porous Si3N4 ceramics with unidirectionally aligned channels

TBA-based freeze-drying and combustion synthesis (CS) are firstly combined to fabricate porous Si3N4 ceramics with controllably unidirectional channels. Uniformly unidirectional channels with variable pore diameters were successfully formed through unidirectional growth of ice. In addition, the residual alpha-Si3N4 content, development of grain morphology and mechanical property of sintered specimens were significantly influenced by the solid content of slurry. Porous Si3N4 ceramics with porosity of 62.5-78.8%, axial compressive strength of 7.3-61.6 Mpa, and transverse compressive strength of 3.3-41.6 MPa were obtained with increasing solid content. (C) 2020 Elsevier B.V. All rights reserved.