The effect of yttrium additions upon the fundamental characteristics of magnesium was investigated by calculated and experimental methods. It was found that the lattice parameter increased and the axial ratio decreased with an increase in the yttrium in solid solution. The approximately linear relationship between Young's modulus and the content of yttrium in solid solution was observed in the single phase solid solution Mg–Y alloys (T4 state). However, Young's modulus was closely relevant to the fraction of second precipitate except the content of saturated yttrium in matrix for the aged Mg–Y alloys (T6 state). The concentration of vacancies increased with the increased content of yttrium in solid solution, which was mainly caused by the atomic size misfit and the difference of valence electrons between yttrium and magnesium.

Effect of Yttrium Addition on Lattice Parameter, Young's Modulus and Vacancy of Magnesium. Q.Peng, J.Meng, Y.Li, Y.Huang, N.Hort: Materials Science and Engineering A, 2011, 528[4-5], 2106-9