Existence form and action mechanism of iron-rich phase in Al-Cu alloy

The study revealed the existence form and mechanism of the iron-rich phase in Al-Cu alloys. The results showed that in the T6 heat-treated state, there were needle-like β-Fe (Al7Cu2Fe) phase and blocky Al7Cu2 (FeMn) phase in Al-Cu alloys. With the increase of Mn/Fe ratio, the volume fraction of blocky Al7Cu2 (FeMn) phase in Al-Cu alloys gradually increased, while the volume fraction of needle-like β-Fe phase gradually decreased. When the extrusion pressure was 75 MPa, the iron-rich phase in Al-Cu alloys with the same Mn/Fe ratio was finer and more dispersed.