Abstract
In this study, time-dependent plastic deformation of micropillars fabricated from low melting point metal Sn (~505K) was investigated at room temperature. Size-dependent strength was first evaluated and creep tests were then performed on the micropillars having diameters of 1 and 5μm. Sn pillars showed significant creep deformation, and creep rate was independent of pillar size. Creep stress exponent was determined to be ~1, and negligible effect of e-beam irradiation on creep rate confirmed that the lattice diffusion must be the predominant creep mechanism. Creep deformation of Sn micropillars, therefore, differs from the dislocation-climb based creep in bulk Sn.
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•Creep tests were performed on Sn micropillars of different sizes that indicated size-independent creep deformation.•Creep stress exponent was evaluated to be ~1 which is indicative of diffusion creep.•In-situ SEM tests under e-beam irradiation was confirmed that lattice diffusion governs creep of Sn pillars, differed from dislocation climb-based creep in bulk Sn.