The Potential Property-Tailoring Effects of Cryogenic Treatment on Pure Zinc

As of late, there has been increasing scope and demand for implants in the biomedical sector, notably in the field of orthopaedics. Within this field, zinc (Zn) is a promising base metal for such implants due to its combination of biocompatibility, mechanical properties, and corrosion response.

For the first time, pure Zn was successfully synthesized using the Disintegrated Melt Deposition (DMD) method and subjected to systematic cryogenic treatment (CT) study, with exposure to varying subzero temperatures (− 20 °C, − 50 °C, − 80 °C, and − 196 °C) for a duration of 24 hours. Densification occurred for all materials (with a 35.9% porosity reduction after exposure to − 50 °C being the most significant), . Microstructurally, CT induced significant grain growth across all exposure temperatures, with − 80 °C conferring the largest grain size (224% increase over as-extruded equivalent). The compression response was also improved slightly after exposure to − 50 °C, with improvements of 2.7%, 2.3%, and 1.0% to compressive yield strength, ultimate compressive strength, and work of fracture, respectively. Exposure to − 196 °C also notably lowered corrosion rates (32.4% reduction compared to as-extruded equivalent).

These findings highlight the ability of CT to not just alter but tailor the individual properties ofZn-based materials, useful in specific applications. Furthermore, this also opens up a new research area for this Hexagonal Closed Pack (HCP) metal and its derivatives.