Synthesis of Cu-Zr-Al/Al2O3 amorphous nanocomposite by mechanical alloying

摘要

Two routes were used to produce Cu-Zr-Al/Al2O3 amorphous nanocomposite. First route included mechanical alloying of elemental powders mixture. In second route Cu_(60)Zr_(40) alloy was synthesized by melting of Cu and Zr. Cu_(60)Zr_(40) alloy was then ball milled with Al and CuO powder. It was not possible to obtain a fully amorphous structure via first route. The mechanical alloying of Cu_(60)Zr_(40), Al and CuO powder mixture for 10 h led to the reaction of CuO with Al, forming Al2O3 particulate, and concurrent formation of Cu62Zr_(32)Al4 amorphous matrix. The thermodynamical investigations on the basis of extended Miedema's model illustrated that there is a strong thermodynamic driving force for formation of amorphous phase in this system. Lack of amorphization in first route appeared to be related to the oxidation of free Zr during ball milling.