Interaction between AE44 magnesium alloy and SiC-Al2O3-SiO2 ceramic foam

The interaction between a molten magnesium alloy AE44 and a SiC-Al2O3-SiO2 ceramics and the resulting reaction products were studied. The samples were investigated using optical and electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. SiO2 was predominantly reduced by Mg during the contact of the magnesium-rich melt with the ceramics. The main reaction product was MgO, whilst Si dissolved in the melt. Two novel tetragonal phases formed at the interface: AlSiRE and AlMgSiRE, having a specific mutual crystallographic orientation relationship. The interactions resulted in strongly connected interfaces between the metal and ceramics after short interaction time; however, interactions lead to disintegration of the ceramics after longer contact time.