The wax positive is invested with a mold made of refractory materials and heated to melt the wax, leaving a narrow cavity Between the core and the investment.
正蜡像外面披盖一个耐火材料制成的模具，然后加热使蜡熔化，留下核心与披盖模具之间一个狭窄的空腔。
2
Study has proved that ceramic shell making by Al-Si system refractory materials with main crystal of Mollite or Kaolinite will be the ideal choice for investment casting ductile iron.