中文摘要：

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＋La_2O_3）混合粉末,制备Ni/Al及（Ni＋La_2O_3）/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＋La_2O_3）/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;La_2O_3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;La_2O_3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＋La_2O_3）/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%。

英文摘要：

Ni/Al and（Ni＋La_2O_3）/Al composites were fabricated by adding micron Ni powder and（Ni＋La_2O_3）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＋La_2O_3）/Al composites were tested by tensile test at room temperature.Results show that Ni/Al composites are mainly composed of Al,Al3 Ni 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;La_2O_3reinforces Al-Ni in-situ reaction to produce more reinforced phase;La_2O_3reduces the agglomeration of Ni powder by retarding the mutual adsorption and aggregated behavior of Ni powder;The tensile strength of（Ni＋La_2O_3）/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 is144 MPa）,the tensile strength of（Ni＋La_2O_3）/Al composites has increased by 158%,107% and 29%respectively.