采用真空熔炼法制备了含硼的铅镁铝合金, 通过扫描电子显微镜、X射线衍射仪、能谱仪和力学性能试验机等研究了硼含量对合金组织与力学性能的影响。结果表明: 添加硼后, 合金中出现了黑色的颗粒状AlB2相, 且与Mg-Mg17Al12共晶组织相伴生; 随着硼含量的增加, AlB2相分布趋于均匀化, Mg-Mg17Al12共晶相增多; 当硼的质量分数为1%时, 合金的力学性能最好, 抗拉强度、硬度和伸长率分别为105 MPa, 160 MPa和6.87%, 室温拉伸断口主要为韧性断裂和准解理断裂的混合特征。

Pb-Mg-Al alloys with boron were prepared by vacuum smelting method, and the effects of boron content on microstructure and mechanical properties of the alloys were studied by scanning electron microscopy, X-ray diffraction, energy spectrum analysis and mechanical property testing. The results show that the black particle phase of AlB2 appeared in the microstructure of the alloy after adding boron, which followed the Mg-Mg17Al12 eutectic structure to grow. The distribution of the AlB2 phase was homogenized and the Mg-Mg17Al12 eutectic phase increased with the increase of boron content. The mechanical properties of the alloy with 1wt% boron were the best, and the tensile strength, hardness and elongation were 105 MPa, 160 MPa and 6.87%, respectively, and its room temperature tensile fracture was mainly the mixture feature of tough fracture and quasi-cleavage fracture.