Enhanced ductility and strength in a cast Al–Mg alloy with high Mg content

• Cast Al–Mg alloys with high Mg content have attracted considerable interest as a result of exceptionally low mass density and enhanced Mg solid-solution strengthening effect. However, poor ductility in this class of cast Al–Mg alloys originating from the increased amount of brittle Al3Mg2 phase presents a challenge. This work aims to improve ductility of a cast Al-10 wt%Mg alloy by prolonging time and/or increasing temperature during solid-solution treatment, hence minimizing the amount of the Al3Mg2 phase. The amounts of Al3Mg2 decrease and the concentrations of solute Mg increase with prolonging time and/or increasing temperature, improving both ductility and strength. Solid-solution treatment at 425 °C for 9 h or at 438 °C for 3 h induces complete dissolution of the Al3Mg2 phase, achieving an average uniform elongation of ~27% accompanied by an average 0.2% offset yield strength of ~186 MPa. The mechanisms improving both ductility and strength are discussed. 

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Keyword

Aluminum alloys

Casting

Ductility

Solid-solution treatment

Strength

Binary alloys

Solid solutions

Temperature

Complete dissolution

Enhanced ductility

Increasing temperatures

Mg content

Phase present

Solid solution strengthening

Solid solution treatment

Uniform elongation

Magnesium alloys

Publication and Content Type

ref (subject category)

art (subject category)