Impression creep behavior of magnesium alloy ZK60

Creep behavior of the ZK60 magnesium alloy was investigated using impression creep technique. The tests were carried out under constant punching stress at high temperatures (175, 200 and 225 degrees C) under low stresses (25, 50, 75 and 100 MPa) and at low temperatures (100, 125 and 150 degrees C) under high stresses (100, 125, 150 and 175 MPa). The creep mechanism of the extruded ZK60 magnesium alloy is grain boundary sliding by dislocation climbing obtained at low temperature and high pressure. At high temperature and under low pressure, the creep mechanism of the extruded ZK60 magnesium alloy is grain boundary diffusion by grain boundary sliding. The initial microstructure of the extruded ZK60 magnesium alloy was composed of mainly Mg phase and a little MgZn phase. Under the conditions of low temperature and high pressure, MgZn2 phase precipitated during creep deformation. Under the conditions of high temperature and low pressure, MgZn2 phase and a small amount of Zr-Zn phase precipitated during creep deformation. The creep resistance of magnesium alloy ZK60 under the conditions of low temperature and high pressure is better than under the conditions of high temperature and low pressure.