Abstract
An aluminum and a zinc powder were mixed to machined chips of AZ31 alloy with various contents, and then the powder mixtures were mechanically alloyed for various milling times using planetary ball mill, for the purpose of recycling of the magnesium alloy. Crystal phase formed in the obtained powder were investigated by X-ray diffraction and Vickers hardness of the powder particles to confirm the formed phases. When Mg-Al system powder mixture was milled for 72 ks by the planetary ball mill, super-saturated solid solution α-Mg and intermetallic compound Mg17Al12 phase are formed, while by milling using the oscillatory ball mill 54 ks was necessary. In the case of mechanically alloyed Mg-2.5 mol% Zn powder, super-saturated α-Mg phase with 2.5 mol% Zn concentration forms. The structures of Mg-28 and 52 mol% Zn powder obtained by the mechanical alloying consist of Mg2Zn2 or MgZn2 and Mg7Zn3 phases and then these phases became amorphous by milling for further time. In the case of mechanical alloying for ternary Mg-Al-Zn system, an icosahedron Mg49(Al,Zn)32 phase, the quasi crystal, forms by the milling for 72 ks in the composition range as following; (30-50)mol% Mg with Al/Zn=(90/10-60/40) molar ratio, Mg-(30-50)mol% Al-20 mol% Zn and Mg-(10-30)mol% Al-40 mol% Zn.
