(Digital Presentation) On the Effect of Sizing on Electrochemical Response and Localized Corrosion Behavior of Alumix 123 P/M Alloy

Abstract

Powder metallurgy (PM) as an additive technique for fabricating parts has been used by many industries such as automotive, aerospace, and medical. However, it has been centered mostly around automotive industry which has benefited from large volume production, low cost, and near-net-shape manufacturing that comes with PM. High demand for producing fuel-efficient and light vehicles in automotive industry provides a driving force for extensive research activity on PM of aluminum alloys. Among different aluminum alloys, PM of 2xxx series are among the best choices due to their good sinterability and mechanical response. But industrial PM parts need post processing treatments such as sizing to meet the real-world applications. While sizing is widely used in industry to provide tighter tolerance, it can also help improving density, fatigue behavior, yield strength, and hardness. But there were very few studies on the effect of sizing on electrochemical response. In this study we produced Alumix 123 PM alloy using a press-and-sinter process and then sizing was applied on some of the samples to compare their long-term electrochemical behavior. The changes in the surface profile and roughness of the samples were investigated using confocal laser scanning microscopy. Electrochemical impedance spectroscopy (EIS) as a powerful technique for investigating long-term electrochemical behavior has been used to find the effect of sizing on corrosion response of Alumix 123 PM. In addition, effect of sizing on localized corrosion and pitting tendency was thoroughly discussed using electrochemical polarization results, scanning electron microscope images, and EIS outcomes.