过去熔模精密铸造壳芯主要是用石蜡、松脂、或是苯乙烯树脂等制造,加热熔模或是燃烧使模气化。这样往往由于热膨胀使壳型容易产生裂纹,给铸件带来不良影响。另外,用上述制芯材料,由于其凝固收缩率大(约0.5～2.5%),铸件尺寸精度也低。水溶性壳芯精密铸造,是用如下壳芯材 In the past, precision cast shell core is mainly made of paraffin wax, turpentine, or styrene resin, etc., and heated to melt or mold to gasify the mold. This is often due to thermal expansion of the shell is easy to crack, cast to bring adverse effects. In addition, since the above-mentioned core-making material has a large solidification shrinkage (about 0.5 to 2.5%), the casting dimensional accuracy is also low. Water-soluble shell casting, is the following shell core material