Preparation and thermomechanical properties of stir cast Al-2Mg-11TiO_2 (rutile) composite

摘要

Al-2Mg-11TiO_2 composite was successfully prepared by the conventional vortex method. The macrostructural observation revealed columnar structure with rutile particles being distributed throughout the matrix in the form of agglomerates. Microstructural observation showed the presence of micro voids in the particle-enriched zone. Electrical resistivity measurement showed a phase transformation at 360 deg C, which was consistent during DSC studies due to the precipitation of TiAl_3 phase. As-cast composite was both hot rolled and cold rolled successfully to 50 and 40 percent reduction, respectively. The mechanical properties of the thermomechanically-worked composite were studied. From fractographic analysis, it was clear that the crack had nucleated at the particle/matrix interface and propagated through the matrix by microvoid coalescence. Ultimate tensile strength of cold worked composite was found to be better than the hot worked material.