Five kinds of molding materials were selected in this study, ie. Green sand mold, CO{sub}2 sand mold, no-bake sand mold, plaster mold and ceramic mold; the first three kinds of mold were usually categorized as sand mold. Results of the effects of these five different molding materials on the microstructure of zinc-based alloy for rapid tools were as follows: (1) the order of the effect on the solidification rate was: ceramic mold>CO{sub}2 sand mold>no-bake sand mold>green sand mold>plaster mold (2) the order of the effect on the grain size of fracture surface structure was: plaster mold>green sand mold>no-bake sand mold>CO{sub}2 sand mold>ceramic mold (3) the order of the effect on the dendritic cell size of the microstructure was: plaster mold>green sand mold>no-bake sand mold>CO{sub}2 sand mold>ceramic mold In short, according to the above-mentioned results, the solidification rates of the zinc-based alloy were highly influenced by the molding materials, ie. the faster the solidification rate, the finer the microstructure.
Molding materials Zinc-based alloy for rapid tools Solidification rate Microstructure