Agricultural waste and natural dolomite for green production of aluminum composites

Metal matrix composites (MMCs), and particularly aluminum matrix composites (AMCs), are beginning to make a substantial contribution to aerospace, automotive, and electronic industry application after more than a quarter-century of intensive study. To fabricate a cost-effective AMC with outstanding mechanical and physical properties the present work utilized two types of natural base reinforcement materials for elaborating AMCs by powder metallurgy technology (PM). The reinforcement materials were an agricultural waste (date palm seeds) and dolomite rocks at 2.5, 5, 7.5, and 10% weight in addition to the aluminum matrix. The morphological and solid-phase characteristics were examined for the fabricated AMC specimens. These tests include X-ray diffraction, and optical and scanning microscopy. The microstructure of the fabricated specimens for both reinforcement materials showed uniform particle size distribution of the waste enforcement material as the PM technology was satisfactory in embedding the waste particles within the aluminum. The AMCs prepared were subjected to different mechanical loads and it was found that the composite reinforced with date palm seeds possess a high hardness property. A higher hardness of 50 HRV at 7.5% enforcement of date palm seeds was obtained compared to dolomite reinforced composite which showed 48.3 HRV at 7.5% enforcement. For the compressive strength, the date palm seeds composite resisted 23.8 MPa at 7.5% and only 16.68 MPa was obtained as a maximum compression resistance for the dolomite reinforced aluminum composite.