Influence of Thermal Processing on Resoloy Wire Microstructure and Properties

Magnesium fine wires are critical components for the fabrication of various absorbable implants. Herein, Resoloy fine wires with diameters of 200 and 500 mu m are prepared with a multipass, cold-drawing technique before undergoing two brief thermal anneals at 350 or 450 degrees C. The as-drawn, cold-worked (CW) wires show small but elongated alpha-Mg grains, with their long axes and basal planes parallel to the drawing direction. Fine, continuous, and uniformly distributed Mg24Dy5 particles are observed within the wire. Although the brief anneals at 350 and 450 degrees C do not alter the texture of the Mg grains or the area fraction, aspect ratio, or distribution of the secondary phase, they do enable recovery and partial recrystallization at 350 degrees C and complete recrystallization at 450 degrees C, thereby providing a wide range of mechanical properties. The 200 mu m wires display slightly higher strengths and slightly lower elongations. Modified simulated body fluid (m-SBF) immersion results indicate that the Resoloy wires exhibit relatively uniform corrosion with rates as low as 1.72 +/- 0.09, 1.44 +/- 0.21, and 1.97 +/- 0.10 mm y(-1) for the cold-worked, 350 degrees C, and 450 degrees C wires with 500 mu m diameter, respectively.

Automated summary

The research focused on preparing Resoloy fine wires with diameters of 200 and 500 μm using a cold-drawing technique followed by thermal anneals at 350 or 450 degrees C. The wires showed elongated alpha-Mg grains with continuous Mg24Dy5 particles. Annealing at 350 and 450 degrees C resulted in recovery and recrystallization, providing a wide range of mechanical properties. Corrosion rates in modified simulated body fluid were relatively uniform across different wire types.