DESIGNING AND FABRICATING PORES IN POROUS MATERIALS

摘要

The most common way to create porous materials is by using coarse powders or lower temperatures to create partial sintering. In such materials, there is a wide variety of pore shapes and sizes. By adding fugitive particles, better control over morphology and pore sizes can be achieved. Starches can be used as fugitive particles to add equiaxed pores with a relatively narrow pore size distribution. Anionic latex binders can cause porosity in tape casting. Pores created in this way will form channels perpendicular to the casting direction. By using indirect freeform methods, it is possible to design and fabricate porous systems with morphologies that have not been achievable before. A model of the desired porous structure is built in a rapid prototyping machine using a polymer as a building material. A ceramic slurry is infiltrated into the polymer model of the pore system and consolidated. The polymer model is then pyrolysed and the ceramic body is sintered.