Property Modification of ZK60 Al-Mg Alloy by Y-Doping

The properties of ZK60 Al-Mg alloy,an advanced gear material for aircraft engine and produced by vacuum induction melting combined with rapid solidification,were modified by doping of yitrium.The influence of the Y-doping on the microstructures and tensile properties was investigated with X-ray diffraction,scanning electron microscopy and tensile behavior measurement.The results show that the Y-doping had a major impact.To be specific,as the Y-content increased,the tensile strength and elongation ratio changed in an increase-decrease mode,maximizing to 378 MPa and 1.26%,respective,at 1%(wt)Y.Addition of 1.0% Y resulted in the formation of a large amount of finer equiaxed grains,coexisting with the fairly large dendrite α-Mg grains(18.1 μm in size).We found that the growth of the dendrite α-Mg grains were responsible for the formation of β-Mg₁₇Al₁₂-phased reticular framework.