Microstructural properties of the Al-Mgx/TiC composites obtained by infiltration techniques

Al-Mgx metal matrix composites reinforced with TiC (56 vol%) were obtained using a pressureless infiltration technique. It was observed that the infiltration rate of these Al-Mgx alloys increases as the magnesium content increases. Through x-ray diffraction (XRD) no reaction phase was detected, only the presence of aluminium and titanium carbide. In addition, some TEM studies were carried out to characterize the interface and the matrix of the composites. These results suggest that the Mg forms a solid solution with the aluminium lattice. Different morphological and chemical characteristics of the precipitated particles are also reported. To get an insight into the interface phenomena in the HREM images, theoretical simulations have been carried out. The hardness of the Al-Mgx/TiC composites increases as the amount of magnesium is increased. Additionally, hardness measurements have been performed with an atomic force microscope (AFM) and comparison with steel values were carried out. The elastic modulus, on the other hand, decreases slightly with magnesium content