Microstructure and mechanical properties of Sn-xGa alloys and solder joints

Huizhe Zhang; Zhaolong Ma; Suyuan Yang; Mengzhuo Fan; Xingwang Cheng

Journal of Materials Research and Technology (Sep 2023)

Microstructure and mechanical properties of Sn-xGa alloys and solder joints

Huizhe Zhang,
Zhaolong Ma,
Suyuan Yang,
Mengzhuo Fan,
Xingwang Cheng

Affiliations

Huizhe Zhang: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing 100081, China
Zhaolong Ma: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; Tangshan Research Institute, Beijing Institute of Technology, Tangshan 063000, China; National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing 100081, China; Corresponding author. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
Suyuan Yang: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; Tangshan Research Institute, Beijing Institute of Technology, Tangshan 063000, China; National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing 100081, China; Corresponding author. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
Mengzhuo Fan: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing 100081, China
Xingwang Cheng: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; Tangshan Research Institute, Beijing Institute of Technology, Tangshan 063000, China; National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing 100081, China

Journal volume & issue: Vol. 26
pp. 3830 – 3839

Abstract

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Though Ga is a promising addition used in third-generation lead-free solders for harsh-environment applications, its influences on βSn structure and mechanical properties of solder alloys/joints are still unknown. This study demonstrated that Ga additions in Sn-XGa (X = 0.5, 1.0, 2.0 in wt%) can moderately refine βSn grains but render the alloys more susceptible to recrystallization during cross-section and polishing. Sn-1.0Ga shows substantially elevated yield/tensile strengths (45.1 MPa/64.9 MPa) compared with pure Sn, attributed to the strong solid-solution strengthening effect of Ga, and it also possesses good tensile ductility of >25%. Compared with pure Sn and Sn-3.0Ag-0.5Cu (SAC305) solder joints on Cu, Sn-XGa/Cu solder joints show significantly reduced dissolution of Cu substrate that benefits in suppressing the formation of primary Cu6Sn5. Among Sn-XGa/Cu, Sn-2.0Ga/Cu joint exhibits high shear strength (69.4 MPa) comparable to that of SAC305/Cu joint (70.5 MPa), owing to the Ga solid-solution strengthening and the extra second-phase strengthening from Cu9Ga4.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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