A new process of compound mold shell for lost foam casting was presented based on foam pattern

which utilized foaming confection to get high quality foam pattern prototypes

then prepared 2

3

layers compound ceramic shell of silica sol-sodium silicate on the surface of foam pattern

finally

prepared the backup layer of ceramic shell with no-bake sand. Dewaxing of ceramic mold shell was carried out in methylene chloride dissolvent at 200

3

00℃ for 30 min

and then the ceramic mold shell was baked at 800 ℃ for 1 h. The results reveal that the shell-making process has the features of simply and short period as well as low cost. The prepared compound shell possesses clean surface and high strength. Meanwhile

ZL101 alloy castings with high quality were obtained with the compound shell.