Comparing physiologically relevant corrosion performances of Mg AZ31 alloy protected by ALD and sputter coated TiO2

SURFACE & COATINGS TECHNOLOGY

卷:395

Article

Peron, Mirco¹  Bin Afif, Abdulla¹  Dadlani, Anup¹  Berto, Filippo¹  Torgersen, Jan¹ 

[1] Norwegian Univ Sci & Technol, Dept Mech & Ind Engn, Richard Birkelands Vei 2b, N-7034 Trondheim, Norway

关键词: Magnesium alloys;    Temporary metallic implants;    Corrosion resistance;    Biocompatible coatings;    Atomic Layer Deposition (ALD);    Sputter;   

DOI  :  10.1016/j.surfcoat.2020.125922

来源: Elsevier

【 摘 要 】

The utilization of Mg alloys for biomedical applications is so far underexplored due to the accelerated corrosion hampering patient recovery post implantation. Here, we explore the effectiveness of corrosion reduction of an AZ31 alloy in Simulated Body Fluid when coated with a 40 nm sputtered TiO2 layer and compare it to a similar coating made by Atomic Layer Deposition (ALD). Potentiodynamic polarization and hydrogen evolution experiments were performed on coated samples having different surface roughness and 3D topologies. Interestingly, ALD layers reduce corrosion current density by 94% on Ra = 118.6 +/- 5.1 nm and 93% on Ra = 4794.3 +/- 49.4 nm, whereas sputtered only by 84% on Ra = 118.6 +/- 5.1 nm and 60% on Ra = 4794.3 +/- 49.4 nm. Particularly on 3D aspects, the ALD coatings are superior, where a scaffold of 85% porosity with 1 mm pore sizes released 68% lower hydrogen compared to the sputtered counterparts. We relate these observations to the higher surface integrity, adhesion strength and lower line-of-sight restrictions of ALD compared to sputter deposition. The results can be interesting for researchers and practitioners aiming to make Mg alloys more commonplace as temporary metallic implant materials.

【 授权许可】

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