Relationship between Biodegradation Rate and Grain Size Itself Excluding Other Structural Factors Caused by Alloying Additions and Deformation Processing for Pure Mg

Abstract

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.