The precipitate behavior of the Mg–10Gd–2Y–0.5Zn–0.3Zr alloy during forging process and
subsequent ageing process at 250 °C is studied in the article. Different from the precipitation
sequence in extruded Mg–Zn–RE alloy, only long period ordered structure and β′ phase
precipitate on the Mg matrix during forging process. The slight kinking is mainly ascribed to
the insufficient and uneven plastic deformation in the forged alloy, which suggests that the
deformation mode of the alloy during forging process is different from that of extruded Mg–
Zn–RE alloy.Amounts of long period ordered structure and β′ phases precipitate on the matrix
with ageing time increasing until 10 h. The peak hardness, 100 HV, of the forged alloy during
ageing process is obtained when the alloy is aged at 250 °C for 10 h. The long period ordered
structure and β′ phase are the main strengthening phases in the peak-aged alloy. Therefore,
the strengthening mechanismof the forged alloy is controlled by the comprehensive effects of
grain refinement and dispersed precipitation of long period ordered structure and β′ phase on
thematrix. The strength improvement of the peak-aged alloy results fromdense precipitation
of long period ordered structure and β′ phase on the matrix.