Abstract
The ultimate tensile strength of 250 MPa, 0.2% proof stress of 150 MPa, and fracture strain of 10% at the as-cast condition for Al-1.5Mn-X alloys, were objective in this development. As ternary elements, Ca, Mg, Ti and Zn were initially chosen and the values in ΔMk of the s-orbital energy level in alloys were adjusted to be less than 0.017. Their proof stress and fracture strain increased and decreased as ΔMk increased, respectively. The composition of promising alloy was decided to Al-1.5Mn-2.4Mg with ΔMk of 0.029 on the basis of the relation between tensile properties and ΔMk. This as-cast alloy showed the σuts σ0.2 and εf of 270, 135 MPa and 18% showing excellent corrosion resistance in the NaCl solution, which resulted in the approximate satisfaction of the objective. The interaction between the proof stress and dislocation density or hindrance for dislocation migration at the constant strain could be explained by ΔMk, which might lead to the indication of solid solution hardening level using this parameter for Al-1.5Mn-X ternary alloys.
