Time-dependent deformation of Sn micropillars

Abstract

In this study, time-dependent plastic deformation of micropillars fabricated from low melting point metal Sn (similar to 505 K) 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 5 mu m. Sn pillars showed significant creep deformation, and creep rate was independent of pillar size. Creep stress exponent was determined to be similar to 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. (C) 2016 Published by Elsevier Ltd