Experiments have been done to assess the way in which the scatter in the measured yield stress of Mg-4Zn (wt %) alloy varies as the ratio of specimen size: grain size is varied (D/d). The value for ratio was varied from 4 to 60. No significant effect was observed and suggestions for this negative result are suggested
In a second set of experiments the ageing response of the same Mg-4Zn alloy was measured for ageing at both 100 and180 . Age hardening was only observed at higher temperature. No time was available to investigate the precipitation in the alloys.
Also a comparison on the effects of temperature ageing on proof stress also investigated. The result shows that by age hardening, proof stress of alloy are effectively increase.