With the rapid expansion of battery-powered electric vehicles (BEVs) in the automotive industry, research interest in lightweight Al alloys as well as their casting processes and applications has increased considerably. The substitution of castable aluminum alloys with superior strengths and electrical conductivity for copper reduces the weight and size of electric induction motors, and improves the energy efficiency and driving range of the BEVs. The present article was intended to give a general introduction into the common cast Al aluminum alloys and their relevant processes, as well as to motivate the development of high strength and conductive Al alloys for the practical realization of Al applications in the motors of the BEVs. A number of cast alloy systems containing Cu, Si, Ni, Mg, Fe, and Ti were evaluated, in comparison to nanostructured wrought Al alloys. The conventional casting processes suitable for Al alloys, high pressure die casting, squeeze casting, and sand casting were described. Strengthening mechanisms including solid solution strengthening, precipitation strengthening, dislocation accumulation strengthening, and grain boundary strengthening were presented. The phenomenon of electrical conduction for Al alloys was outlined. The mechanical properties and electrical properties of the recently developed Al alloys for casting and deformation processes were comprehensively listed and critically reviewed in association with microstructural characteristics.
1 January 2010 in Annals of Clinical Microbiology and Antimicrobials
Aluminum-made settings are widely used in healthcare, schools, public facilities and transit systems. Frequently-touched surfaces of those settings are likely to harbour bacteria and be a potential source of infection. One method to utilize the effectiveness of copper (Cu) in eliminating pathogens for these surfaces would be to coat the aluminum (Al) items with a Cu coating. However, such a combination of Cu and Al metals is susceptible to galvanic corrosion because of their different electrochemical potentials.
The natural brittleness of oxide ceramics heavily inhibits their more extensive applications. In present research, a highly flexible Al2O3/Al/Al2O3 hybrid composite was fabricated by employing plasma electrolysis oxidation to in situ grow alumina layers on Al foil, in which an outside layer of nanostructured polycrystalline oxide ceramic was composed of nanosized grains with the size of around 17 nm. Due to shear band formation, nanosized circle bubbles prolonging the crack path, grain rotation, and deformation, the fabricated Al2O3/Al/Al2O3 hybrid composite contains no observable cracks even after being bent on a cylindrical bar with a curvature of 1.5 mm. The composite exhibits alumina stiffness at the elastic stage and aluminum ductility during plastic deformation, which provides high flexibility with the well‐integrated properties of the components. In a synergistic interaction, the alumina on the outside exhibited a strain of 0.33% at room temperature, which was higher than optimum value of 0.25% presented by reported most flexible oxide ceramics. With the unique characteristics and properties, the Al2O3/Al/Al2O3 composite demonstrates a great potential for various engineering applications.
Corrosion performances of several metallic materials (Al6061 and Al319 alloys, 304 stainless steel and grey cast iron) in the ethanol-gasoline alternative fuels were investigated. Cyclic potentiodynamic polarization tests were used to study their corrosion behavior. Anodizing and plasma electrolytic oxidation (PEO) techniques were used to produce oxide coatings on the Al6061 and Al319 alloys, and the corrosion properties of these coatings in the alternative fuel environments were also evaluated. The results showed that, the 304 stainless steel, Al6061 and the coating materials are compatible with the alternative fuels. The oxide coatings on both Al alloys provided effective corrosion protection in the alternative fuel environments.