| 摘要 |
PURPOSE:To improve the permeability of a precision casting mold and to prevent the cast defect caused by the residual gas in the mold. CONSTITUTION:A shell 50 is formed by using slurry 30 containing binder 31, refractory powder 32 and lost material powder 33 lost by burning at a specific temp. The lost material powder 33 is burnt and lost in a process of burning the shell 50 and innumerable fine cavities are formed by losing the lost material powder 31 in the mold 60 for precision casting to improve the permeability of the mold 60. |
