Development of Cu-(Gr + W) Hybrid Surface Composites Fabricated through Friction Stir Processing

The present work focusses on development of copper(Cu) hybrid surface composite through friction stir processing (FSP). The hybrid surface composites were developed by reinforcing graphene and tungsten particles into the copper matrix. The reinforced particle volume fractions varied from 0 to 100%, and the process was carried out at a rotational speed of 900 rpm and tool travel speed of 100 mm/min. The processed composites zone is extracted and further analyzed for the metallography, hardness, wear rate and electrical conductivity studies. Microstructural analysis revealed refinement of copper matrix and uniform distribution of tungsten and graphene particles. Among the processed composite samples, the Cu-50%Gr + 50%W hybrid surface composite demonstrated greater wear resistance about 64%, increase in microhardness of 72%, and a slightly reduced electrical conductivity of 4% IACS. This indicates the co-addition of tungsten and graphene by FSP is a promising strategy for enhancing Cu mechanical properties without significantly impairing its electrical conductivity.