Abstract
Magnesium matrix composites show improved wear resistance, enhanced strength and creep resistance in comparison with their monolithic counterparts, on the other hand keep low density and good machinability. Internal friction measurements are suitable tool to detect changes in the microstructure of thermally or mechanically loaded composites.
Samples from pure magnesium reinforced with zirconia nanoparticles were thermally cycled between room temperature and increasing upper temperature of thermal cycle. After thermal cycling amplitude dependence of decrement was measured.
Very high valued of the logarithmic decrement were described to the poor binding between the matrix and ceramic nanoparticles. The influence of cyclic bending on the damping behaviour of the same nanocomposite was determined at room temperature.
Measured decrease of the resonant frequency indicates the stiffness loss as a function of cycling.