稀土氧化物(La2O3或CeO2)对搅拌摩擦加工制备Ni/Al复合材料组织和性能的影响

采用搅拌摩擦加工（FSP）的方法制备Ni/Al复合材料，并在此基础上添加不同种类稀土氧化物（La₂O₃或CeO₂），通过SEM、EDS、XRD、电子探针（EPMA）和室温拉伸试验研究稀土氧化物对FSP制备Ni/Al复合材料组织和性能的影响。结果表明：Ni/Al复合材料复合区有较明显的Ni粉团聚物存在，Ni-La₂O₃/Al、Ni-CeO₂/Al复合材料中Ni粉团聚物数量减少，尺寸减小。La₂O₃和CeO₂均对Al-Ni原位反应有较大影响，能够促进Al-Ni原位反应的进行，生成更多增强相。Ni-CeO₂/Al复合材料与Ni-La₂O₃/Al复合材料相比，复合区组织更加均匀，增强颗粒Al₃Ni含量更多。La₂O₃和CeO₂均能显著提高FSP制备Ni/Al原位复合材料的抗拉强度。Ni-La₂O₃/Al复合材料的抗拉强度达到221 MPa，Ni-CeO₂/Al复合材料的抗拉强度达到238 MPa，两者相比于Ni/Al的复合材料抗拉强度（166 MPa）分别提高了33.1%和43.4%。

Influence of rare earth oxides (La2O3 or CeO2) on the microstructure and properties of Ni/Al composites fabricated by friction stir processing

The Ni/Al composites were fabricated by friction stir processing (FSP) by adding different kinds of rare earth oxides (La₂O₃ or CeO₂). The effects of rare earth oxides on the microstructure and properties of Ni/Al composites were studied by SEM, EDS, XRD, electron probe microanalysis (EPMA) and tensile test at room temperature. The results show that Ni/Al composite has more obvious agglomerates of Ni in composite zone. The distribution of Ni power content and size increase in Ni-La₂O₃/Al and Ni-CeO₂/Al composites. La₂O₃ or CeO₂ can reinforce Al-Ni in-situ reaction to produce more reinforced phase. Ni-CeO₂/Al composite has better uniform organization and the volume fraction of Al₃Ni enhances in composite zone. The tensile strength of Ni/Al composite is significantly increased when adding La₂O₃ or CeO₂. The tensile strength of Ni-La₂O₃/Al and Ni-CeO₂/Al composites can reach 221 MPa and 238 MPa, respectively. Compared with the Ni/Al composites (166 MPa), the tensile strength has increased by 33.1% and 43.4%, respectively.