The effects of alloying with Cu and Mn and thermal treatments on the mechanical instability of Zn-0.05Mg alloy

Abstract

The detrimental effect of natural aging on mechanical properties of zinc alloys restricts their application as bioresorbable medical implants. In this study, aging of Zn-0.05Mg alloy and the effect of 0.5 Cu and 0.1 Mn (in weight percent) addition on the microstructure and tensile properties were studied. The alloys were cold rolled, aged and annealed; aiming to investigate the effects of precipitates and grain size on the mechanical properties and their stability. TEM analysis revealed that in ultrafine-grained binary Zn-0.05Mg alloy, the natural aging occurred due to the formation of nano-sized Mg 2 Zn 11 precipitates. After 90 days of natural aging, the yield strength and ultimate tensile strength of Zn-0.05Mg alloy increased from 197±4 MPa and 227±5 MPa to 233±8 MPa and 305±7 MPa, respectively, while the elongation was drastically reduced from 34±3% to 3±1%. This natural aging was retarded by adding the third element at either 0.1Mn or 0.5Cu quantities, which interacted with Mg in Zn solid solution and impeded the formation of Mg 2 Zn 11 precipitates. The addition of Cu and Mn elements increased alloy's strength, ductility, and its mechanical stability at a room temperature. The measured tensile strength and elongation were 274±5 MPa and 41±1% for Zn-0.1Mn-0.05Mg and 312±2 MPa and 44±2% for Zn-0.5Cu-0.05Mg, respectively. Annealing the alloys at elevated temperatures caused increase in both grain size and dissolution of secondary phases, and both affected alloy deformation mechanisms.

Recent research and progress of biodegradable zinc alloys and composites for biomedical applications: Biomechanical and biocorrosion perspectives

“…The addition of 0.05 wt% Mg to the extruded Zn significantly increased its σ UTS to 225 MPa and its elongation (ε) to 26%, showing increases of more than ~2 times in σ UTS and ~1.9 times in ε over extruded pure Zn (with σ UTS = 112 MPa and elongation = 14%). Ardakani et al [ 179 ] reported the effects of the addition of 0.1 wt% of Mn on the microstructure ( Fig. 4 c–d) and tensile properties of binary Zn-0.05 Mg alloys.…”

A Novel High-Strength Zn-3Ag-0.5Mg Alloy Processed by Hot Extrusion, Cold Rolling, or High-Pressure Torsion

“…1.1 9 10 À3 361 423 5.2 Liu et al [23] Cold Deformation Processes Hot Extrusion + Cold Drawing Zn-0.02Mg 1 9 10 À3 388 ± 2 455 ± 2 5.4 ± 0.3 Wang et al [24] Hot Extrusion + Cold Drawing Zn-0.08Mg after 0 days 3.3 9 10 À3 250 266 30 Jin et al [25] Zn-0.08Mg after 1 year 3. [26] Cold Rolling Zn-0.5Cu-0.05Mg 2 9 10 À3 241 ± 5 312 ± 2 44± 2 Ardakani et al [27] Hot Rolling + Cold Rolling Zn-4Cu 1 mm/min 327 393 39 Li et al [28] Hot-Warm (100°C ) Rolling…”

Recent Developments in Zn-Based Biodegradable Materials for Biomedical Applications

“…The addition of Mg to Zn matrices resulted in the formation of hypoeutectic microstructures. These microstructures are comprised of α-Zn dendrites and a eutectic mixture of α-Zn and Mg 2 Zn 11 phases [ 71 , 77 , 78 , 79 ]. The presence of intermetallic particles (Mg 2 Zn 11 ) due to the addition of Mg in Zn significantly enhanced the mechanical properties of Zn matrices.…”