1. By the mechanical infiltrations including sizing, inertial impaction & diffusion interception, friction, sedimentation and so on, the infiltration efficiency is in direct ratio to pore size of the foam ceramic mesh. The smaller mesh, the stronger interception ability to small grains.

2. Effects of depositional layer or cake layer. The capture ability is strengthened based on the sediment of particles in the melt and tortuous connective ragged netted supporter.

3. The rough surface, formed by the cracks on netted supporter, increases the interface energy of melted aluminum and solid ceramic surface, accelerating disorder of particle flow in melted aluminum, contributing to the capture and sediment of solid particles.

4. Due to the microcosmic cracks and pinholes on the surface of netted skeletal supporter, the fluoride with strong appendiculate force to the particles, such as Al2O3, is pre-subsided. They contribute to the whole effect of cake layer and strong chemical absorption ability. Therefore, the capability of capture and adsorption of impurity phase particles is further strengthened.

5. Moreover, the effects of temperature field in the flow and metal melt structure during smelting definitely cause poor concentrations of alloy melts. The metal alloys undergo the processes of distribution à assemble à redistribution à reassemble, which are good processes for alloying treatment. Some metal phases and compounds with high melting points are assembling and getting larger. They are easier to be filtered and captured after exiguous mixed phases assemble and become larger. This is proved by changes of the concentrations of H、Al₂O₃、Fe phase 、Ti phase between pre and post infiltration. The changes become more obvious by using two-stage infiltration or hole grade thick board infiltration.

Therefore, under the same conditions, new type foam ceramic filter board has higher removing rate of impurity phase in melted aluminum. The static pressure difference of pre & post filtration is greater along with the time change. [H] content in melted aluminum of pre & post infiltration is changed obviously. Of course, the smaller pore size of foam ceramic material you choose, the higher purity of melted aluminum you have.