添加La2O3对搅拌摩擦加工制备Ni/Al复合材料组织和性能的影响
Influence of La2O3 addition on structure and properties of Ni/Al composites fabricated by friction stir processing

采用搅拌摩擦加工（FSP）方法在Al基体中添加微米级Ni粉及（Ni+La2O3）混合粉末，制备Ni/Al及（Ni+La2O3）/Al复合材料。采用SEM、EDS及XRD对复合区微观结构及相组成进行分析，采用室温拉伸试验对Ni/Al、（Ni+La2O3）/Al复合材料力学性能进行了测试。结果表明：Ni/Al复合材料中主要成分为Al、Al3Ni和Ni粉团聚物，Ni粉团聚物尺寸粗大，形貌呈壳-核结构，核为团聚的Ni，壳为Al3Ni增强相层；La2O3对Al-Ni原位反应有较大影响，能够强化Al-Ni原位反应，生成更多增强相；La2O3阻碍了Ni粉的相互吸附和聚拢行为，从而减少了团聚现象；（Ni+La2O3）/Al复合材料的抗拉强度可以达到186 MPa，与Al基体（抗拉强度72 MPa）、纯Al FSP（抗拉强度90 MPa）、Ni/Al复合材料（抗拉强度144 MPa）相比，其抗拉强度分别提高了158%、107%、29%。 Ni/Al and (Ni+La2O3)/Al composites were fabricated by adding micron Ni powder and (Ni+La2O3) mixed powder to the Al matrix with means of the friction stir processing. The microstructures and phase composition of the composite zone were analyzed by SEM, EDS and XRD. Mechanical properties of Ni/Al and (Ni+La2O3)/Al composites were tested by tensile test at room temperature. Results show that Ni/Al composites are mainly composed of Al, Al3Ni and agglomerates of Ni powder, the size of agglomerates of Ni powder is very coarse and the morphology is core-shell structure. The core is composed of agglomerated Ni, the shell is composed of the reinforced phase layer of Al3Ni; La2O3 reinforces Al-Ni in-situ reaction to produce more reinforced phase; La2O3 reduces the agglomeration of Ni powder by retarding the mutual adsorption and aggregated behavior of Ni powder; The tensile strength of (Ni+La2O3)/Al composites can reach 186 MPa. Compared with the Al matrix(tensile strength is 72 MPa), the FSPed Al(tensile strength is 90 MPa) and Ni/Al composites(tensile strength is 144 MPa), the tensile strength of (Ni+La2O3)/Al composites has increased by 158%, 107% and 29% respectively. 国家自然科学基金（51465044，51364037）；江西省自然科学基金（20142BAB216019）