Correlation between microstructure and corrosion behaviour of Bi-Zn solder alloys. (19th May 2019)

• Record Type: Journal Article
• Authors: Septimio, Rudimylla S.; Arenas, Maria A.; Conde, Ana; Garcia, Amauri; Cheung, Noé; Damborenea, Juan de
• Is Part Of: Corrosion engineering, science, and technology. Volume 54:Number 4(2019)
• Page Start: 362
• Page End: 368
• Publication Date: 2019-05-19
• Subjects: Solder alloys -- Bi-Zn alloys -- microstructure -- corrosion resistance; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1080/1478422X.2019.1600836
• Languages: English
• ISSNs: 1478-422X

Abstract

ABSTRACT: Bi-Zn solder alloys with different Zn contents (1.5, 2.7 and 5wt-%) were prepared by casting and the correlation between the microstructure and corrosion behaviour by mean of direct current electrochemical tests was studied. The surface analysis of the hypoeutectic Bi-Zn alloy samples revealed the presence of needle-like ZnO and very small agglomerated spherical particles. By contrast, eutectic alloy presented the formation of a uniform and compact film of ZnO, which is related to the better distribution of Zinc in the Bi-rich matrix. Despite the increase in Zn content compared to the hypoeutectic alloy, the corrosion rate showed similar values regardless of its content in the alloy. The Bi-5wt-% Zn alloy presented the highest limiting current density, and consequently, the highest degree of corrosion of the studied alloys. The pro-eutectic phase consisting of large and thick Zn fibres is preferentially dissolved, promoting a selective attack that penetrates inside the sample.