For that seal required auto cast aluminum parts, such as cylinder block, cylinder head, intake manifolds, brake valve body, etc., during the pressure sealing test of cast aluminum parts, the presence of defects in porous media will lead to the leakage, even cause a large number of sealed waste, and that these defects of cast aluminum parts are often machined by the pressure test can be found, resulting in a serious waste of work hours, raw materials and energy.

To deal with the high rate of automobile cast aluminum parts, and save that parts could be scrapped because of cast aluminum parts defects, it is so important to take some measures to deal with these problems in the production. The current technology is the most commonly used infiltration, i.e. plugging. The so-called "infiltration" is under certain conditions, the infiltration agent to infiltrate the porous cast aluminum parts gap, after curing so that the filler into the pores of the pore wall fused with the casting, blocking the pores, so that cast aluminum parts can be meet the pressure, seepage and leak-proof technology and other conditions.