부산대학교 도서관

The purpose of this work is to investigate the effect of Er on mechanical properties and corrosion behavior of 6061 alloys. Thetensile strength and corrosion resistance of the 6061 alloys first enhanced and then declined synergistically with the increaseof Er content. Microstructure analysis revealed that the morphology, composition, and potential of secondary phases changedsignificantly as Er content changed. When the Er content is 0.6 wt%, the needle-like β-AlFeSi phases transformed into thegranular AlFeSiEr phases, which led to an increase in the tensile strength of the 6061 alloys. At the same time, compared withthe acicular β-AlFeSi phases, the granular AlFeSiEr phases own a lower potential difference with α-Al, which weakened thecorrosion of the micro-galvanic couples. However, as the Er content is higher than 0.6 wt%, the granular AlFeSiEr phaseschanged to block-shaped, which can adversely affect the tensile strength and corrosion resistance of the 6061 alloys. EISresults show that, compared with the acicular β-AlFeSi phases, the 6061 alloys with granular AlFeSiEr phases form moreuniform oxide films and exhibit better corrosion resistance. This study indicates that through appropriate Er addition, thesynergistic enhancement of tensile strength and corrosion resistance of the 6061 alloys can be obtained, which is of greatsignificance for the strengthening and long-term service of aluminum alloys.