High-strength extruded Mg–Al–Ca–Mn alloy

We have developed an extraordinary high-strength rare-earth-free magnesium (Mg) alloy by extruding a direct chill cast Mg–3.5Al–3.3Ca–0.4Mn (wt.%) ingot. The as-extruded sample exhibited a tensile 0.2% proof stress of 410 MPa, an ultimate tensile strength of 420 MPa and an elongation to failure of 5.6%. The high strength is attributed to the combined effect of fine dynamically recrystallized grains pinned with fragmented Al–Ca intermetallic compounds, nanoscale plate-like Al–Ca precipitates, spherical Al–Mn–Ca precipitates and a strong basal texture.

► Hot extrusion was performed on a direct chill cast Mg–Al–Ca–Mn sample. ► Extraordinary high-strength low-cost rare-earth-free Mg alloy was fabricated. ► Tensile yield strength is 410 MPa, UTS is 420 MPa and elongation is 5.6%. ► Fine DRXed grains, nano-scale Al–Ca and Al–Mn–Ca precipitates were formed. ► Strong basal texture was formed.