Characterisation of Mechanical and Damping Properties of Porous AZ91 Mg Alloy

An open cell porous AZ91 magnesium alloy was fabricated via powder metallurgy process. The porosity and pore size of the porous material can be varied in the ranges of 40-80% and 0.75-1.75 mm, respectively. In comparison of porous pure aluminum, the porous magnesium alloy shows serrated compressive stress-strain curves with much longer plateau regions and enhanced damping capacity. The damping increases with either increasing the porosity or decreasing the pore size, and shows a positive strain amplitude effect. The increased dislocations near the cell walls when loaded are responsible for the damping enhancement. This is further demonstrated by adding Cu particulates into the cell wall material.