Year: 2026
Type: article
Abstract: The deformation behavior of solders based on β-Sn is influenced by a high homologous operating temperature and microstructural heterogeneity. In this study, the deformation mechanisms of single-crystal and polycrystalline Sn were investigated using high-temperature nanoindentation combined with post-indentation microscopy. Constant strain-rate and dynamic mechanical analysis tests were conducted between 30℃ and 180℃ (0.6–0.9 T m ) to quantify hardness, pop-in, and creep constitutive parameters. Hardness decreases with increasing temperatures (as expected), while pop-in loads shift to lower values at higher temperatures, indicating thermally assisted activation of plastic deformation. Indentations into polycrystalline Sn regions exhibit higher stress exponents ( n ≈ 6.8–7.4) and activation energies at moderate temperatures than indentations in single grains remote from any boundaries, reflecting the influence of grain boundary constraints in accommodating plasticity. At higher temperatures, both microstructures converge toward lower stress exponents and activation energies, suggesting a transition toward deformation mechanisms increasingly governed solely by thermally activated processes. Microstructural characterization reveals slip band formation, dislocation localization, and grain boundary sliding, demonstrating that deformation in polycrystalline Sn at these temperatures results from the combined effects of intragranular dislocation activity and intergranular strain accommodation.
Source: JOM
Authors: J. Tien, D. F. Bahr
Institution: Purdue University West Lafayette
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,790
Awards: G1982182222, G5943655122
OpenAlex ID: W7203719087