In this research, the precipitation sequence investigation and phase identification in Mg–3Nd–0.2Zn–
0.46Zr (wt.%) system were performed using differential scanning calorimetry (DSC) and transmission
electron microscopy (TEM) techniques. The results showed the precipitation sequence to be: Super saturated
solid solution (SSSS)?Clustering of atoms/short range ordering?b00 ?b0 ?b which shows that low
zinc content (less than 0.5 %wt) does not influence the precipitation sequence. TEM studies revealed that
in addition to prismatic planes, b0 0 precipitates lie on pyramidal planes in Mg matrix, which has not been
reported previously in this system. Further investigation using TEM and aging experiments showed that
these precipitates are responsible for the age hardening of the alloy. Furthermore, the kinetic studies
showed that quenched-in vacancies play an important role in the early stage of precipitation and formation
of b0 0 while formation of b0 is dominantly diffusion controlled process and quenched-in vacancies are
no longer effective.