Preparation and evaluation of cu-zn-gnss nanocomposite manufactured by powder metallurgy

Abstract

Room-temperature ball milling technique has been successfully employed to fabricate copper-zinc graphene nanocomposite by high-energy ball milling of elemental Cu, Zn, and graphene. Copper powder reinforced with 1-wt.% nanographene sheets were mechanically milled with 5, 10, 15, and 20 wt.% Zn powder. The ball-to-powder weight ratio was selected to be 10:1 with a 400-rpm milling speed. Hexane and methanol were used as a process control agent (PCA) during composite fabrication. The effect of PCA on the composite microstructure was studied. The obtained composites were compacted by a uniaxial press under 700 MPa. The compacted samples were sintered under a controlled atmosphere at 1023 K for 90 min. The microstructure, mechanical, and tribological properties of the prepared Cu-Zn GrNSs nanocomposites were studied. All results indicated that composites using hexane as PCA had a uniform microstructure with higher densities. The densities of sintered samples were decreased gradually by increasing the Zn percent. The obtained composite contained 10 wt.% Zn had a more homogeneous microstructure, low porosity, higher Vickers hardness, and compression strength, while the composite contained 15 wt.% Zn recorded the lowest wear rate. Both the electrical and thermal conductivities were decreased gradually by increasing the Zn content.