Investigation of Microstructure, Hardness and Wear Behavior of Powder Metal Al 7020 / SiC / Nano Graphene Doped Hybrid Composites

Abstract

Al 7020 aluminum alloy is mainly preferred in many engineering applications, especially in the aviation and space sectors. Nano graphene (Gr) particles were selected for the study due to their hybrid composite structure, microstructure, mechanical properties, lubrication properties, lightness, and small size compared to the matrix and reinforcement element. For this purpose, SiC and nanographene powder particles were added to the aluminum matrix as reinforcement phases in the study, and composite-hybrid test samples were produced. In the production of Al7020 powder metal matrix SiC/nanographene doped test samples, 10% SiC ceramic phase reinforcement by weight was applied to the matrix material at a fixed rate, and nanographene particle reinforcement was added at the rates of 0.25%, 0.50%, and 1.0%. The prepared matrix powder mixtures were mixed in a high-energy ball mill at 300 RPM and 240 minutes to ensure homogeneous distribution in terms of matrix/reinforcement. After mixing, the powder mixtures were compressed at room temperature using a pressing pressure of 650 MPa. The obtained raw density test samples were sintered at 600°C for 60 minutes under Argon gas flow. Thus, the effect of SiC-nano graphene reinforcement on density, microstructural, hardness, and wear (25N, 900m) results were evaluated. The pore amount increased in the samples containing reinforcement elements. The highest hardness value was 108.476 HBN in the sample containing Al-10%SiC-0.5%Gr.