Enhancing the longevity of magnesium implants with cold-sprayed Ta/Ag coatings: Optimization of corrosion and wear resistance

Magnesium alloys are gaining attention for biomedical implants due to their lightweight nature and bonemimicking mechanical properties. However, their high reactivity and vulnerability to corrosion restrict their long-term application in biomedicine. This study explores the potential of enhancing corrosion resistance and wear performance of magnesium through tantalum/silver (Ta/Ag) composite coatings manufactured by cold spray for durable implant devices. The coatings exhibited adhesive strengths ranging from 22.5 to 27.5 MPa, sufficient to prevent delamination. The inclusion of silver in the composites effectively protected the tantalum matrix from corrosion, preserving its structural integrity over a long period of corrosion. Additionally, a higher silver content improved fatigue wear resistance by inhibiting crack propagation and increased the hardness-toYoung's modulus ratio through in-situ mechanical mixing of Ag and Ta during wear, which also reduced the generation of free debris particles. Among the tested compositions, the Ta-5Ag composite offered the best overall protection, optimizing corrosion resistance, wear performance, and mechanical stability. These results indicate that cold sprayed Ta/Ag composite coatings are a promising approach to making magnesium alloys more viable as long-term implant materials.