TEM analysis of the interfaces between the components in magnesium matrix composites reinforced with SiC particles

A microstructural analysis of the interfaces between the components of cast composites based on magnesium and magnesium alloys (MgAl8, MgZn6 and MgRE3; RE: rare-earth elements) reinforced with SiC particles is presented. Transmission electron microscopy (TEM) investigations allowed to establish the adhesive character of the bonds between the SiC particles and Mg matrix as well as MgAl8, MgZn6 matrix alloys, while the composites based on Mg alloys containing rare-earth elements exhibited a reaction layer between the components. Occasionally, the interfaces between the components contained precipitates derived from the instability of the conditions or parameters of the production processes. Energy-dispersive spectrometry and electron diffraction analyses allowed to identify the precipitates as the SiO2, MgO and Fe-containing compounds.