LAUSR

This work studied the relationship between biodegradation rate and grain size itself, excluding other structural factors such as segregations, impure inclusions, second phase particles, sub-structures, internal stresses and textures caused by alloying additions and deformation processing for pure Mg. A spectrum of grain size was obtained by annealing through changing the annealing temperature. Grain boundary influenced the hardness and the biodegradation behavior. The hardness was grain size-dependent, following a typical Hall–Petch relation: HV=18.45+92.31d−12. The biodegradation rate decreased with decreasing grain size, following a similar Hall–Petch relation: Pi=0.17−0.68d−12 or Pw=1.34−6.17d−12. This work should be helpful for better controlling biodegradation performance of biodegradable Mg alloys through varying their grain size.