Development of New High-Strength and Heat-Resistant Mg-Zn-Y-X (X=Zr and Ag) Casting Alloys

Yuichi Ienaga; Kenshi Inoue; Tokuteru Uesugi; Yorinobu Takigawa; Kenji Higashi

doi:10.4028/www.scientific.net/MSF.783-786.384

Paper Titles

The Orientation Dependence of Strain Hardening and Texture Development in an Extruded Magnesium Alloy
p.363

Effect of Thermomechanical Processes on Twin Roll Casted Magnesium Alloy Sheets
p.369

Room Temperature Screw Form Rolling of AZ91D Magnesium Alloy through Processing by Extrusion-Torsion Simultaneous Working
p.375

Fabrication of Mg Alloy Single Crystals Containing Rare Earth Elements and their Mechanical Behavior
p.380

Development of New High-Strength and Heat-Resistant Mg-Zn-Y-X (X=Zr and Ag) Casting Alloys
p.384

Microstructure and Defect Structure Evolution in Ultra-Fine Grained MgAlZn Alloy
p.390

Effect of Plane Strain on the Microstructure and Texture of AZ31 Sheet with Various Reduction Ratios
p.396

Compressive Characteristics of AZ91 Containing Sn Alloy with the Microstructure
p.402

Investigation of Properties of CaO Added Wrought Mg-Zn-Y and Mg-Y-Zn Alloys
p.407

HomeMaterials Science ForumMaterials Science Forum Vols. 783-786Development of New High-Strength and...

Development of New High-Strength and Heat-Resistant Mg-Zn-Y-X (X=Zr and Ag) Casting Alloys

Abstract:

In order to develop a high strength and heat-resistant magnesium alloy, we focused on controlling microstructure of Mg₉₆Zn₂Y₂ (at %) casting alloy by the addition of a 4th element. Initially, we investigated the effects of zirconium addition and cooling rate for grain refinement on microstructure and mechanical properties. Consequently, Mg_95.8Zn₂Y₂Zr_0.2 casting alloy contains fine equiaxed grains (approx. 0.01 mm), and it exhibits tensile and fatigue properties equivalent to or higher than those of commercial aluminum alloys at high temperature above 473 K. At 523 K, this alloy exhibited a tensile strength of 223 MPa nearly twice that of A4032-T6 alloy used in typical automotive pistons. The Mg_95.8Zn₂Y₂Zr_0.2 casting alloy also reveals sufficient ductility and good castability, characteristics not common in current heat-resistant magnesium alloys. Next, we focused on controlling microstructure of Mg₉₆Zn₂Y₂ casting alloy by the addition of Ag. Mg₉₆Zn₂Y₂ cast alloy is composed of alpha-Mg phase, long-period stacking ordered phase and Mg₃Zn₃Y₂ phase; on the other hand, Mg-Zn-Y-Ag cast alloy had 4th phase by an addition of Ag. A substantial increase in yield strength at room temperature, without grain refining, was the result.