硅酸铝短纤维增强镁基复合材料的界面反应及其热力学分析

用晶化的硅酸铝短纤维作增强体, 用磷酸铝作黏结剂制得预制体, 用AZ91D作基体金属, 通过挤压浸渗工艺制备镁基复合材料。通过光学显微分析、 XRD衍射分析、 SEM扫描分析等, 初步观察研究了硅酸铝短纤维增强镁基复合材料的界面反应规律和反应产物。结果表明: 用硅酸铝短纤维增强AZ91D镁合金通过浸渗挤压法制备镁基复合材料是可行的; 镁与磷酸铝黏结剂反应后在界面上生成一定数量的MgO颗粒和少量的MgAl₂O₄颗粒, 致使硅酸铝增强纤维和镁合金基体之间形成较强界面结合; 另外, 在硅酸铝短纤维的晶化处理过程中, 由于非晶态SiO₂的析出, 导致Mg₂Si脆性相在界面附近产生, 从而对该复合材料的力学性能产生一定影响。 

Interface reaction and thermodynamic analysis on the magnesium alloy matrix composite reinforced with alumina silicate short fibers

A magnesium alloy matrix composite was fabricated by squeeze cast with the preform made of crystallized aluminum silicate short fibers as reinforcement and aluminum phosphate as binder. The reaction products were investigated by optical microscopic, XRD and SEM, and the chemical reaction at the interface between the short fiber and matrix was analysed by thermodynamic analysis. It is shown that the alumina silicate fiber can be chosen as the reinforcement of Mg matrix composites, and an ideal stronger interface was formed by the chemical reaction between magnesium alloy matrix and aluminum phosphate binder due to the produce of MgO particles and a little MgAl2O4 particles. In addition, a brittle Mg2 Si phase was precipitated at the interface through the reaction between amorphous SiO2 and Mg in the magnesium alloy matrix, which affects the mechanical properties of the magnesium alloy matrix composite.