Ly. Wei et al., PRECIPITATION HARDENING OF MG-ZN AND MG-ZN-RE ALLOYS, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 26(7), 1995, pp. 1705-1716
The age-hardening response of two cast Mg-Zn-RE alloys has been invest
igated and compared with that of a binary Mg-Zn alloy. The microstruct
ures of the aged specimens were examined by analytical electron micros
copy. Formation of a fine dispersion of rodlike beta(1)' precipitates
is the main cause for age hardening, while extensive precipitation of
disc-shaped beta(2)' coincides with the onset of overaging. Rare earth
additions retard the formation of beta(2)' precipitates and thus post
pone overaging. Four different orientation relationships between beta(
2)' precipitates and matrix were found and explained in terms of the n
ear-CSL model.