Solid solution strengthening behaviors in binary Mg-Y single phase alloys

Solid solution effects on the mechanical behavior of binary Mg-Y single phase alloys have been investigated in a temperature range from ambient to 350 degrees C with yttrium contents between 0.20 and 1.88 at.%. At room temperature, the hardness increases with the increasing Y content as H(v0.5) (kg mm(-2)) = 31.12 + 13.23 Y (at.%). The yield strength increases linearly with c(n), where c is the solute atom concentration and n=1/2 or 2/3. However, the yield strength deviates from the c(n) power-law at temperature over 100 degrees C. This deviation observed in tensile tests over a temperature range 150-250 degrees C can be correlated with the dynamic strain ageing (DSA) effects due to the interaction between dislocations and solute Y atoms, which is evidenced by the serrated flow, as well as the local minimum and plateau in the temperature dependences of yield and ultimate strength. Other possible strengthening mechanisms have been also discussed. All rights reserved (C) 2008 Elsevier B.V. All rights reserved.