Ultrafine-Grained Zn-Mg-Sr Alloy Synthesized by Mechanical Alloying and Spark Plasma Sintering

Zinc materials are considered promising candidates for bioabsorbable medical devices used for the fixation of broken bones or stents. Materials for these applications must meet high mechanical property requirements. One of the ways to fulfil these demands is related to microstructure refinement, particularly the decrease in grain size. In the present work, we combine two powder metallurgy techniques (mechanical alloying-MA, and spark plasma sintering-SPS) to prepare Zn-1Mg-0.5Sr nanograin material. The microstructure of compacted material consisted of Zn grains and particles of Mg₂Zn₁₁ intermetallic phases from 100 to 500 nm in size, which resulted in high values of hardness and a compressive strength equal to 86 HV1 and 327 MPa, respectively. In this relation, the combination of the suggested techniques provides an innovative way to form extremely fine microstructures without significant coarsening during powder compaction at increased temperatures.