La2O3含量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 content on the microstructure and properties of Ni/Al composites fabricated by friction stir processing

摘要:

采用搅拌摩擦加工方法在Al基体中添加不同La₂O₃含量的混合粉末(Ni+La₂O₃),制备 (Ni+La₂O₃)/Al复合材料。采用SEM、EDS、 EPMA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+La₂O₃)/Al复合材料力学性能进行了测试。结果表明,随着La₂O₃含量的增加,(Ni+La₂O₃)/Al复合材料的组织和性能先变好后变差。当La₂O₃添加量达到5%时,复合材料中Al₃Ni增强颗粒分布均匀、颗粒数量最多,块状的Ni粉团聚减少,其抗拉强度达到最大值215MPa,相比Ni/Al复合材料(抗拉强度176MPa),其抗拉强度提高了22%；当La₂O₃的添加量为7%时,复合材料中Al₃Ni增强颗粒含量减少,块状Ni粉团聚重新出现,抗拉强度下降至201MPa。

Abstract:

_{: (Ni+La2O3)/Al composites were fabricated by means of adding the mixed powder of (Ni+La2O3) with different La2O3 content to the Al substrate in the Friction Stir Processing (FSP) period. The microstructures of the composite zone were analyzed by SEM and EDS, the element distribution of the composite zone were analyzed by EPMA, the phase composition was examined by XRD, the mechanical properties of the composites were tested by tensile test at room temperature. Results show that: The microstructure and properties of (Ni+La2O3)/Al composites trend to be better firstly and then worse with increasing of La2O3 contents. When the contents of La2O3 are 5%, the contents of Al3Ni particles increase and the distribution of particles becomes uniform,the massive Ni agglomerates are decreased, so the tensile strength of the composites is the highest with 215MPa, which is increased by 22% than that of Ni/Al composites(The tensile strength is 176MPa); When the contents of La2O3 are 7%, the contents of Al3Ni particles decrease and the massive Ni agglomerates reappear, the tensile strength of the composites decreased to 201MPa.}