The Effect of Pre-Stretching Treatment on the Microstructure, Mechanical Properties, and Corrosion Resistance of 7075 Aluminum Alloy used in PEMFC

Among various fuel cells, proton exchange membrane fuel cells (pemfc) have many advantages, such as low-temperature operation, fast starting, and high energy density. therefore, the pemfc can be widely applied in power generation, portable electric devices, and hybrid vehicles. because of their high strength, low density, and corrosion resistance, heat-treatable aluminum alloys, such as 7075, are widely used in industry and for application to pemfc. in addition to mechanical properties, corrosion resistance is also very important for working in an industrial environment. t6 heat treatment is recommended for this purpose, but this tempering treatment is sensitive to corrosion and stress corrosion cracking (scc). in this study, a 4% pre-stretch after solution was applied to samples to investigate its effect on scc resistance. the results showed that with this treatment, the precipitates immigrate from the grain boundary to the interior of the grains and improve the scc properties, which is very important for use in pemfc. the results also show that a 4% pre-stretching after solution improves both tensile strength and elongation, and a tensile strength of 473 mpa with 12% elongation can be achieved by this heat treatment.