New precision casting process: adding anti-cracking agent to the shell surface slurry

Add 8% of the anti-cracking agent to the surface layer zircon powder slurry, and stir evenly. The powder-to-liquid ratio of 3.3 to 3.4:1 can also be used to prepare the surface slurry in the order of adding silica sol→powder stirring for 8h→anti-cracking agent stirring for 5h→wetting agent stirring for 2h and defoaming agent stirring for 1h.

After the module is dipped, sprinkle 100 mesh zircon sand or 100 mesh white corundum sand. Under the conditions of a dry surface layer at a temperature of 23℃ and a relative humidity of 60%, blow air at a wind speed of 4-6 (m/s) and dry the surface. Time ≤ 2h.

The surface layer dried by strong wind not only greatly shortens the drying time, the coating has no cracks, no cracks, no shedding, no bulging, no delamination, and the wet strength of the surface layer is significantly improved, and the inner cavity and the outer cavity of the module The mold is dried at the same time, and the quality of the cast precision castings will not appear cracks.