Effects of 0.2Mo+0.2Zr Addition on Microstructure and Tensile Properties of Al–9Si–0.3Fe–0.15Mn Casting Alloy

The Al–9Si–0.3Fe–0.15Mn alloy was chosen as the base alloy, 0.2Mo and 0.2Zr were added in combination (0.2Mo+0.2Zr) to maintain ductility improve strength tensile properties. 0.2Mo+0.2Zr addition showed improvement both ultimate (?UTS) (160 MPa) fracture strain (?f) (7.1%) at as-cast conditions, compared with those (145 MPa, 6.1%) of alloy. increment ?UTS ?f by 8% 14%, respectively, obtained addition. eutectic ?-Al smallest minimum nanoindentation hardness (HIT, min), showing high Al or low ?Mke? due heavy micro-segregation existed a continuous phase led ductility. size cell structure caused dense tangles dislocations about 250 nm, which corresponded similar regions It found on basis properties that usage gravity casting method Mo Zr, suggested possibility for application because Si particles refined, characterized content region Zr atoms. inhomogeneity grains including IMCs acted harmonic