RECYCLING OF WASTE OYSTER SHELLS AS A REINFORCEMENT MATERIALS FOR AA7075 ALLOY

Abstract

In the current research, oyster shells have been recycled by reinforcing with aluminum alloy AA7075 using the stir casting method. The oyster shells (OS) were washed and milled via high energy ball mill. The produced castings were fabricated with various content of the OS particles as (0-15 Wt.%). The effect of oyster shell particles (OS) on the microstructures, mechanical properties and corrosion behavior of AA7075/OS composites has been studied. The microstructure results revealed a uniform distribution of oyster shell particles within AA7075 matrix. Compression, brinell hardness, and impact tests of the sample were carried out to identify the mechanical properties of the composite. The hardness was increased from 37%, 61% and 88.7% for AA7075 reinforced with 5, 10 and 15% OS composite compared with unrienforced AA7075. On the other hand, the ultimate compressive strength was improved from 10.7%, 19.8% and 25.9% for AA7075 reinforced with 5, 10 and 15% OS composite compared with unreinforced AA7075. The corrosion rate and weight loss method were carried out by immersing the specimens in 0.1M NaOH and 0.1M H 2 SO 4 solutions. Results revealed that the rate of corrosion and mass loss were decreased with an increase of mass fraction up to 15%.