Ce对Fe-Ni膨胀合金凝固组织的影响研究结果表明:经Ce处理后,Fe-Ni膨胀合金中形成了大量的高熔点Ce2O3包芯Al2O3复合物,尺寸约为2μm.错配度理论计算表明,Ce2O3的某些低指数面与Fe-Ni膨胀合金的低指数面具有7·1%的较低错配度,因此Ce2O3作为非均匀形核核心使膨胀合金凝固组织由完全的柱状晶变为完全的等轴晶组织.Ce在凝固组织的等轴晶晶界上以Ce2O3、Ce2O2S和CeS形式存在,具有阻止晶粒长大的作用. Ce on the solidification microstructure of Fe-Ni alloy The results show that: after Ce treatment, a large number of high-melting Ce2O3 clad Al2O3 composite formed in the Fe-Ni alloy, the size of about 2μm. Mismatch theory calculations show , Some of the low index surfaces of Ce2O3 and the low index surface of the Fe-Ni expanded alloy have a lower mismatch of 7.1%. Therefore, the Ce2O3 as the inhomogeneous nucleation center changes the solidified structure of the expanded alloy from a completely columnar crystal to Complete equiaxed grain structure.Ce exists in the form of Ce2O3, Ce2O2S and CeS on the equiaxed grain boundaries of the solidified structure, and has the effect of preventing grain growth.