Preparation and damping capacity of three-dimensional network Ti₂AlC/Mg matrix composites

The Ti₂AlC porous ceramic preforms were prepared by precursor method in this paper, and the Ti₂AlC/Mg matrix composites with the dense three-dimensional network structure were prepared by auxiliary pressure infiltration process. The microstructure and phase composition of the composites were investigated by scanning electron microscope (SEM) and X-ray diffractometer (XRD), and the damping performance of the composites was tested by vibration analyzer. The results show that, the composites have the two-scale three-dimensional network structure at the macro and micro levels. At the constant temperature, the maximum loss tangent values of the composites are 0.13 and 0.15 at 1 Hz and 10 Hz, respectively, increasing by about 30% and 67% compared with AZ91D, the damping performance is enhanced. Under the constant strain, the composites have the maximum loss tangent value at the highest test temperature. In the two test conditions, both of the storage modulus is higher than that of AZ91D. From the view of the balance between internal friction and storage modulus, the composites not only have the wider application temperature range, but also have the better damping-strength balance.