Characterization of the Sn78Bi22 alloy as an environmentally friendly lead-free solder

Stamenković, Uroš; Marković, Ivana; Manasijević, Dragan; Božinović, Kristina; Nedeljković, Milan; Kovačević, Avram

doi:10.5937/EcoTER26410S

Conference Object Open access M33

U. Stamenković et al EcoTER_2026.pdf (2.54MB)

2026

Stamenković, Uroš
Marković, Ivana
Manasijević, Dragan
Božinović, Kristina
Nedeljković, Milan
Kovačević, Avram

University of Belgrade – Technical Faculty in Bor

Proceedings [Elektronski izvor] - 32st International conference Ecological Truth & Environmental Research - EcoTER'26, Sokobanja, Serbia, 24-26 June 2026

410

416

English

M33 - Conference paper at an international conference, printed in full

The development of reliable lead-free solder alloys remains essential for applications in the electronics industry. This paper investigates the mechanical, electrical, and microstructural properties of a Sn78Bi22 solder alloy. The alloy was prepared by melting and casting, followed by a homogenization heat treatment. Tensile testing, Vickers microhardness measurements, electrical conductivity testing, and SEM/EDS microstructural analysis were performed at room temperature. The investigated alloy exhibited enhanced ultimate tensile strength (~93 MPa) and microhardness (45.5 HV0.05) compared with pure Sn, while electrical conductivity decreased to 5.4 MS/m. These changes were attributed to solid-solution strengthening, grain refinement, and the formation of a Bi-rich secondary phase, which also promoted brittle fracture during tensile testing. Microstructural observations revealed a Sn matrix with finely distributed Bi-rich phases, particularly along grain boundaries. The results contribute additional experimental data on the mechanical, electrical, and microstructural characteristics of non-eutectic Sn-Bi solder alloys.

Sn78Bi22 alloy, mechanical properties, electrical conductivity, microstructure

DOI

10.5937/EcoTER26410S

ISBN

978-86-6305-171-3

URI

https://repozitorijum.tfbor.bg.ac.rs/handle/...

Scopus Web of Science OpenCitations OpenAlex

dc.creator	Stamenković, Uroš
dc.creator	Marković, Ivana
dc.creator	Manasijević, Dragan
dc.creator	Božinović, Kristina
dc.creator	Nedeljković, Milan
dc.creator	Kovačević, Avram
dc.contributor	Radojević, Ana
dc.title	Characterization of the Sn78Bi22 alloy as an environmentally friendly lead-free solder
dc.date.issued	2026
dc.publisher	University of Belgrade – Technical Faculty in Bor
dc.identifier.doi	10.5937/EcoTER26410S
dc.identifier.isbn	978-86-6305-171-3
dc.type	conferenceObject
dc.source	Proceedings [Elektronski izvor] - 32st International conference Ecological Truth & Environmental Research - EcoTER'26, Sokobanja, Serbia, 24-26 June 2026
dc.citation.spage	410
dc.citation.epage	416
dc.language.iso	en
dc.type.version	publishedVersion
dc.citation.rank	M33
dc.subject	Sn78Bi22 alloy
dc.subject	mechanical properties
dc.subject	electrical conductivity
dc.subject	microstructure
dc.description.abstract	The development of reliable lead-free solder alloys remains essential for applications in the electronics industry. This paper investigates the mechanical, electrical, and microstructural properties of a Sn78Bi22 solder alloy. The alloy was prepared by melting and casting, followed by a homogenization heat treatment. Tensile testing, Vickers microhardness measurements, electrical conductivity testing, and SEM/EDS microstructural analysis were performed at room temperature. The investigated alloy exhibited enhanced ultimate tensile strength (~93 MPa) and microhardness (45.5 HV0.05) compared with pure Sn, while electrical conductivity decreased to 5.4 MS/m. These changes were attributed to solid-solution strengthening, grain refinement, and the formation of a Bi-rich secondary phase, which also promoted brittle fracture during tensile testing. Microstructural observations revealed a Sn matrix with finely distributed Bi-rich phases, particularly along grain boundaries. The results contribute additional experimental data on the mechanical, electrical, and microstructural characteristics of non-eutectic Sn-Bi solder alloys.
dc.rights.license	CC-BY-NC-ND
dc.rights.uri	https://creativecommons.org/licenses/by-nc-nd/4.0/
dc.date.accessioned	2026-11-03T10:27:38Z
dc.description.provenance	Submitted by ustamenkovic@tfbor.bg.ac.rs on 2026-10-21 20:10:51.157874, with 2 file(s). Approved by Милица Ницуловић (mniculovic@tfbor.bg.ac.rs) on 2026-11-03T10:27:38Z.
dc.identifier.uri	https://repozitorijum.tfbor.bg.ac.rs/handle/123456789/6158
dc.identifier.fulltext	https://repozitorijum.tfbor.bg.ac.rs/bitstream?id=f1f740e4-d72d-4738-8093-41b4d1ba2475


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