硅酸铝短纤维增强AZ91D复合材料的界面微观结构及力学性能

Interface microstructure and mechanical property of (Al_2O_3-SiO_2)_(sf)/AZ91D composite

以晶化的硅酸铝短纤维(Al2O3-SiO2)sf为增强体、用磷酸铝为预制体粘结剂,通过挤压浸渗工艺制备了(Al2O3-SiO2)sf/AZ91D镁基复合材料。通过光学显微镜、TEM和HREM分析研究了复合材料的界面微观结构和界面反应产物。结果表明:用挤压浸渗法制备的硅酸铝短纤维增强AZ91D镁基复合材料的界面厚度约为100 nm,界面上除有一定数量的MgO颗粒和少量的MgAl2O4和Mg2Si颗粒外,还有少量的MgP4等反应产物存在;硅酸铝增强纤维与镁合金基体之间形成了较强界面结合,界面微观结构比较理想。力学性能测试表明,与AZ91D基体合金相比,复合材料的室温抗拉强度提高了约18%,弹性模量提高了约58%。

The magnesium alloy matrix composite was fabricated by the squeeze cast with the preform made of crystallized aluminum silicate short fibers as the reinforcement and aluminum phosphate as the binder. The interface microstructure and reaction products were investigated by optical microscope, TEM and HREM. It is shown that the thickness of the interface of the metal matrix composite （MMC） is about 100 nm, and there are not only lots of MgO grains and a small quantity of MgAl2O4 and Mg2Si nano grains, but also a small quantity of MgP4 nano grains on the interface. The stronger interface binding force and ideal interface structure are formed between the magnesium alloy matrix and the alumina silicate fibers. Compared with the properties of the AZ91D alloy, the tensile strength of the MMC increases by 18% at room temperature, and the Young＇s modulus increases by 58%.