壁厚效应对砂型铸造ZA27合金组织与性能的影响

通过对不同壁厚的ZA27合金铸件在砂型铸造条件下凝固过程的观察，研究探讨了壁厚效应对砂型铸造ZA27合金组织、键全度和机械性能的影响。实验结果表明，随壁厚的加大，铸件键全度降低，由分散性缩孔趋向于集中性缩孔，显微组织有粗化趋势，机械性能降低；但随工艺因素的改变，壁厚效应可消除或消弱，在砂型铸造时严格控制其工艺参数，在壁厚小于60mm范围内均可获得优质铸件。

The Effects of Sectional Sensitivity on Structure and Properties of ZA27 Alloy in Sand Casting

The solidification processes of ZA27 alloy with different section sizes in sand castingare investigated. The investigation on effects of sectional sensitivity on microstructure, soundnessand mechanical properties of ZA27 alloy shows that the soundness becomes worse with increase insection, more internal shrinkage appears, and grain size becomes larger, which result in decreasein mechanical properties. However, proper casting process can improve the structure and properties in heavy section castings. Satisfactory sand castings can be produced even though the castingsection reaches 60mm provided strictly controlling the casting process parameters.