Assessment of Mechanical and Antimicrobial Properties of Die-Cast Al Scrap-Cu Alloy for Contact Surface Application

Abstract

Contact surface bacterial infections are on the increase globally. Metallic silver and copper with excellent antibacterial properties have been reported in the literature but seldom use for structural application due to high cost and relative scarcity. In this work, Al-xwt%Cu alloys with 2.5, 7.5, 5.0, 10.0, 15.0, 20.0, and 25.0 wt% Cu were developed and produced via die-casting technique with mould pre-heating temperature of 300°C. Mechanical and antimicrobial properties of the die-cast Al-xCu products were investigated following standard procedure. The results revealed an enhancement in tensile and compressive strength of the alloy with increase in wt% addition of Cu up to 20 wt% and thereafter decline. The peak yield tensile and compressive strength of 200.641 and 373.26 MPa which falls within the recommended value of 110–240 MPa for structural handrail contact surface application was recorded in the sample with 20% wt Cu addition in aluminum thus obtaining a 538 and 80% improvement respectively compared to control sample with 0% Cu. Results of antimicrobial property of the developed Al-xCu alloy antimicrobial property enhancement and the performance is dependent on the specific exposed bacteria strains and weight concentration of Cu. The efficacy of antibacterial assessment of Al-xCu alloy indicated the addition of Cu beyond 20 wt% relative to control sample within each bacteria yielded 238, 141, 95 and 94% antibacterial enhancement on Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli respectively. Hence Escherichia coli has more resistance to the antibacterial property of Al-xCu alloy