Paper number 533
|ELECTRON MICROSCOPY ANALYSIS OF SQUEEZE CAST AL18B4O33W/AZ91D COMPOSITES|
G. Sasaki, M. Yoshida, J. Pan and H. Fukunaga
Department of Mechanical Engineering, Hiroshima University
Kagamiyama 1-4-1, Higashi-Hiroshima, 739-8527, Japan
|Summary||Aluminum borate (Al18B4O33) whisker reinforced AZ91D composites fabricated by squeeze casting process have good mechanical properties at high temperature and aging effects. In as-cast composites, MgAl2O4 layer is produced at the interface between Al18B4O33 and Mg matrix with a uniform thickness of 20-30 nm. There are some preferred orientations at Al18B4O33/ MgAl2O4 and MgAl2O4/ Mg interfaces. This uniform MgAl2O4 layer prevents the direct reaction between the whisker and Mg matrix during heat-treatment under 700°C. For T6 treatment, the precipitates were distributed uniformly in the matrix. Consequently, the whiskers were scarcely damaged, so that the degradation of high temperature properties is very little.
||Keywords|| electron microscopy, aluminum borate whisker, magnesium alloy, interfacial reaction, heat stability, squeeze casting, mechanical properties.
Theme : Metal Matrix Composites ; Characterisation and Modelling
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