Effects of different Fe content on microstructure and properties of hot extrusion recycled aluminum alloy were investigated by optical microscopy

scanning electron microscopy

universal tensile machine and microhardness tester.Meanwhile

the evolution mechanism of iron-rich phase morphology was also described.The results show that the increase of Fe content is beneficial to suppress grain growth during extrusion and high temperature heat treatment process.Therefore the grain size is decreased gradually with Fe content increase

and the maximum decrease degree is reached to 25%.After hot extrusion

the iron-rich phase in the regenerated aluminum is broken and distributed in a strip shape along the extrusion direction.With the increase of Fe content

the area fraction and average length of iron-rich intermetallic phase are gradually increased

then area fraction and average length reach the maximum value when Fe content is 0.10%～1.24%

respectively

however

the roundness of the iron-rich phase is reduced slightly with the Fe content increase.Meanwhile

the tensile strength

yield strength and elongation of recycled aluminum present a decreasing trend with the increase of Fe

where maximum amplitude reach about 10.4%

23.2%and 46.0%

respectively

while the microhardness is increased gradually to21.7%.The fracture morphology is changed from a pure ductile fracture to a mixed fracture mode.