Compressive Behavior at Ambient Temperature of ZK60-xDy Magnesium Alloys

Effects of the compressive rate, specimen dimension, specimen orientation and microstructure on the compressive property at ambient temperature of extruded ZK60-xDy alloy rods were investigated. The results show that the specimen dimension, specimen orientation and microstructure except the compressive rate play a significant role on the compressive property. The compressive strength σbc increased significantly by the improving amplitude of 65~110 MPa with increasing the height/diameter ratio h/φ of the cylindrical compressive specimen from 0.5 to 1, however it was not enhanced further as h/φ increased to 2. With increasing the value of h/φ, the yield stage on the compressive curve was strengthened gradually, and meanwhile the compressive macro-fracture changed from the inverted "V" type to pure shear fracture with an angle of 45°. Compared with the specimen whose axial direction was parallel to the transverse direction, σbc was enhanced by the improving amplitude of 60~120 MPa for the specimen whose axial direction was parallel to the extrusion direction. When small amount of Dy (0.31%) was added into ZK60 alloy, σbc was increased from 500 MPa to 540 MPa. However, it slightly decreased to 515 MPa again when the Dy content increased to 4.32%.