u00b0 c followed by water quenching then aging for 2 hours at 200 u00b0 c were expanded to alloys no 1 5 of example i not only were the strength and ductilities of the alloys no 2 5 typically superior to their as rolled condition but they were also superior to the most widely used commercial mg alloy az91 the strength of these alloys was also more than double that of the known commercial bio absorbable polymer implants alloy no 1 with 0 6 ca did not recover good strength and ductility these results are presented in table v the above alloys after annealing and aging were tested in vitro in phosphate buffered saline solution simulated body fluid sbf at 37 u00b0 c to simulate bio absorption rate in vivo in these tests h 2 evolution is a direct measure of mg alloy corrosion and the results are presented in table vi as graphically seen in fig1 the corrosion rates and h 2 evolution in vitro in synthetic body fluids sbf were very dependent upon composition alloy 1 demonstrated the lowest corrosion rate while alloy 4 had the highest in table vi these results are further correlated with the target times for a fixation device implant that needs to support bone during a healing time of eight weeks and also needing to be completely absorbed within six months as indicated in the table alloys no 1 and 3 which have low amounts of zn of 1 0 and 1 3 respectively achieve these targets macro alloying with 2 zn or more was seen as being detrimental to the corrosion rate namely it being too fast to allow for adequate bone development and healing to examine the effect of the rolling practice on the alloys.