Investigation of hardness and wear properties of graphene reinforced Al-Cu alloy produced by powder metallurgy method

Al matrix composites have been used in many industries such as aerospace, defence, electronics and automotive due to their low density, high mechanical strength, stifness, good corrosion resistance and high impact resistance. Various oxides, carbides and borides are preferred as reinforcement materials for Al matrix composites. Graphene has outstanding mechanical, thermal and electrical properties and it is a potential candidate as reinforcement additive for Al matrix composites to obtain enhanced mechanical properties. In the present study, Al-4Cu matrix composite powders were produced from elemental powders of Al and Cu via mechanical alloying technique. Also, graphene reinforcements were synthesis via electric arc discharge method in our laboratories by previously optimized process parameters as few-layered platelets. Powder metallurgy routes were used to produce composites having different amount of graphene as 0 0.25 0.50 and 1 wt%. The starting powders of Al, Cu and graphene were mechanically alloyed for different durations up to 9 h. The characterization of mechanically alloyed powders were performed using differential thermal analysis (DTA), X-Ray diffraction (XRD) and powder particle size measurement. Mechanical alloyed powders uniaxially pressed at 400 MPa and binding removaled at 300oC for 2 hours and sintered at 590 °C for 3 hours under Ar atmosphere. Structural and physical properties of sintered samples were investigated through Archimedes density, optical microscopy (OM), Scanning electron microscope (SEM), XRD techniques. Additionally, mechanical characterization of bulk sample were performed in terms of hardness and reciprocating wear tests. As a result, the increasing amount of graphene and MA duration increased the wear resistance of the material. Graphene reduce the hardness of the material.