机构地区: 上海交通大学材料科学与工程学院金属基复合材料国家重点实验室
出 处: 《上海交通大学学报》 2004年第9期1433-1437,共5页
摘 要: 用电磁分离技术(EMS)制备了原位Al/Mg2Si功能梯度复合材料(FGMs),并采用复合盐变质剂对初生Mg2Si增强相进行细化和变质.实验结果表明,制备的圆棒状复合材料在近外壁区域形成φ(Mg2Si)=17.5%相偏聚层,提高了表面硬度.电磁力参数、铸型温度场和铸型尺寸是影响增强颗粒分布的主要因素.通过控制外加磁场的电磁力参数和温度场,可实现复合材料中φ(Mg2Si)在径向呈既定的梯度规律变化.相同条件下,铸型内径越大,复合材料内部区域的增强颗粒所占比例就越高,增强颗粒的分布就越分散. In-situ Al/Mg2Si functional graded materials (FGMs) were prepared by electromagnetic separation technology (EMS) and the primary Mg2Si phases were refined and modified by introducing compound salt. It was found that the reinforcing particles formed at the outer periphery of the cylinder-like samples reaches as high as 17.5% and thus the surface hardness is greatly improved. The distribution of the reinforcing particles is mainly influenced by the electromagnetic processing parameters, the temperature field and the dimensions of the mould. By adjusting the electromagnetic processing parameters and temperature field distribution, a regular graded distribution can be obtained along the radial direction of the samples cross profile. Under the similar conditions, larger inter diameter of the mould leads to higher ratio of the primary Mg2Si particles' amount in the interior area of the composite materials and higher dispersiveness of the particles.