熔模铸件的尺寸精度受熔模线收缩率影响较大，通过降低熔模的线收缩率是提高铸件尺寸精度的有效措施。 本文研究了某 K648 高温合金铸件空心熔模结构对铸件尺寸精度的影响。 结果表明，将熔模局部截面按 4.5~5 mm进行空心化设计，可以缓解熔模平面缩陷和局部变形的问题。 162 全新模料制备的空心熔模平均线收缩率由 1.16% 降低至 0.54% ，铸件尺寸精度可由 CT7 级提高至 CT5 级，铸件实际线收缩率由 2.70% 降至 2.41% 。 为高精度、厚大铸件的熔模铸造工艺设计提供了参考依据。

The dimensional accuracy of investment castings is greatly affected by the linear shrinkage rate of the wax mold. Reducing the linear shrinkage rate of the wax mold is an effective measure to improve the dimensional accuracy of castings. The influence of a hollow wax mold on the dimensional accuracy of a K648 superalloy casting was studied. The results show that a hollow wax mold can alleviate the problems of plane shrinkage and local deformation of the investment mold. The average linear shrinkage of the wax mold is reduced from 1.16% to 0.54%, the dimensional accuracy of the casting can be improved from CT7 to CT5, and the shrinkage of the casting is reduced from 2.70% to 2.41%. The present research can provide a reference basis for improving the dimensional accuracy of thick and large investment castings.