Interface reaction and thermodynamic analysis on Al2O3-SiO2(sf)/AZ91D composite
(1.广东省广州市华南理工大学机械工程学院
2.Department of Mechanical and Electronic Engineering, Henan Institute of Science and Technology,Xinxiang 453003, China
3.College of Mechanical Engineering, South China University of Technology, Guangzhou 510640, China)
2.Department of Mechanical and Electronic Engineering, Henan Institute of Science and Technology,Xinxiang 453003, China
3.College of Mechanical Engineering, South China University of Technology, Guangzhou 510640, China)
Abstract: Al2O3-SiO2(sf)/AZ91D composite was fabricated by squeezing infiltration using preform made of crystallized aluminum silicate short fibers as reinforcement and aluminum phosphate as binder. The interfacial reaction products were investigated by optical microscopy, X-ray diffractometry, scanning electron microscopy, and the thermodynamics was discussed. It is shown that alumina silicate fibers are ideal candidates for the reinforcement of the Mg alloy matrix composites, and the perfect strong interfaces were formed by the chemical reaction between Mg in the magnesium alloy matrix and aluminum phosphate binder through generation of MgO particles. In addition, brittle Mg2Si phase was precipitated at the interface through the reaction between amorphous SiO2 and Mg in the magnesium alloy matrix, which affects the mechanical property of the composite.
Key words: Al2O3-SiO2(sf)/AZ91D composite; magnesium matrix composite; interface reaction; alumina silicate short fiber; aluminum phosphate binder; thermodynamic analysis