Comparative Study of Zinc Cold-Spray Coating and Pre-treatments for Magnesium Alloys

Journal Article · Sun Mar 01 00:00:00 EST 2026 · Journal of the Minerals Metals & Materials Society (JOM)

DOI:https://doi.org/10.1007/s11837-026-08237-1· OSTI ID:3030341

Niverty, Sridhar ^[1]; Pole, Mayur ^[1]; CHRISTUDASJUSTUS, JIJO ^[1]; Jun, Jiheon ^[2]; Haag, James ^[1]; Ajantiwalay, Tanvi ^[1]; Kalsar, Rajib ^[1]; Joshi, Vineet ^[1]

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1. Pacific Northwest National Laboratory (PNNL)
2. ORNL

Magnesium (Mg) alloys are appealing for automotive lightweighting owing to their high specific strength. However, their susceptibility to corrosion in harsh environments remains a major challenge. Conventional industrial pre-treatment coatings, including zinc phosphate, chromate conversion, and non-chromate conversion, often exhibit discontinuities and microcracks, leading to localized corrosion near fasteners and parting lines. This study investigates cold-sprayed zinc (Zn) coatings as a novel pre-treatment alternative for high-pressure die cast (HPDC) AZ91 Mg alloys, demonstrating significant improvements in wear and corrosion performance. Cold spray produces uniform and robust coatings, reducing wear rate by over 50% and reducing corrosion rate by over 99.3%, as measured by evolved hydrogen release, compared to traditional pre-treatments. Multimodal corrosion testing reveals that Zn cold-spray coatings form a protective layer during exposure, minimizing general and filiform corrosion, and exhibiting corrosion potential (Ecorr) that is nobler by ~ 400 mV than the surfaces of both pre-treated and uncoated AZ91. Scalability of cold spray for selective application around multimaterial joints further strengthens their industrial viability. This work establishes Zn cold-spray coatings as highly effective pre-treatment solutions for the advancement of corrosion resistant Mg alloy components in automotive applications.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 3030341
• Journal Information: Journal of the Minerals Metals & Materials Society (JOM), Journal Name: Journal of the Minerals Metals & Materials Society (JOM) Vol. TBD
• Country of Publication: United States
• Language: English