Correlation between microstructure and corrosion behaviour of Bi-Zn solder alloys

Author(s)

Septimio, Rudimylla S. ^[1] ; Arenas, Maria A. ^[2] ; Conde, Ana ^[2] ; Garcia, Amauri ^[1] ; Cheung, Noe ^[1] ; de Damborenea, Juan ^[2]

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, Dept Mfg & Mat Engn, BR-13083860 Campinas, SP - Brazil

^[2] CSIC, CENIM, Natl Ctr Met Res, Madrid - Spain

• Document type: Journal article
• Source: CORROSION ENGINEERING SCIENCE AND TECHNOLOGY; v. 54, n. 4, p. 362-368, MAY 19 2019.
• Web of Science Citations: 0

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. (AU)

• FAPESP's process: 17/16058-9 - Solidification Microstructures and Wear Resistance of Zn-Al-Bi Monotectic Alloys
• Grantee: Noe Cheung
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 17/15158-0 - Characterization of microstructure and properties in the evaluation of alloys for thermal interface contact
• Grantee: Amauri Garcia
• Support Opportunities: Regular Research Grants