Work

In-situ EBSD investigation on shear deformation mechanism and fracture behavior of Ni@CF composite solder joints

Year: 2025

Type: article

Abstract: This study employs in-situ electron backscatter diffraction (EBSD) and miniature shear testing to investigate microstructural evolution and fracture in 1 wt% Ni-coated carbon fiber (Ni@CF)-reinforced SAC305 solder joints. Real-time observations reveal that unreinforced SAC305 joints exhibit orientation-dependent shear deformation. β -Sn grains with a smaller angle between their c -axis and the shear direction undergo preferential plasticity and rotation, while grains with a larger c -axis/shear direction angle remain rigid. Strain localization at the brittle Cu 6 Sn 5 IMC/Sn interface triggers rapid crack propagation. In contrast, Ni@CF additions impart dual strengthening mechanisms: grain refinement via heterogeneous nucleation and crack blunting/deflection at Ni@CF/matrix interfaces, redirecting cracks into the solder matrix and promoting energy dissipation. Consequently, the 1 wt% Ni@CF composite solder joint achieves a 304 % higher fracture strain (1.112 vs. 0.275) and sustained plastic deformation. The approach directly probes microstructural responses (e.g., grain rotation, crack propagation) under shear loading, advancing understanding of composite solder mechanics.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.11.112

Authors: Yihui Du, Xiaoliang Ji, Yishu Wang, Fu Guo

Institutions: Beijing University of Technology, Beijing Information Science & Technology University

Language: English

Topic: Electronic Packaging and Soldering Technologies

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,640

Funders: National Natural Science Foundation of China, Natural Science Foundation of Beijing Municipality