Elevated and cryogenic temperature micropillar compression of magnesium–niobium multilayer films

Abstract

The mechanical properties of multilayer films consisting of alternating layers of magnesium and niobium are investigated through micropillar compression experiments across a broad range of temperatures. The data collected from the variable temperature micropillar compression tests and strain rate jump tests are used to gain insight into the operative deformation mechanisms within the material. At higher temperatures, diffusion-based deformation mechanisms are shown to determine the plastic behavior of the multilayers. Diffusion occurs more readily along the magnesium-niobium interface than within the bulk, acting as pathway for magnesium diffusion. When individual layer thicknesses are sufficiently small, diffusion can remain the dominant deformation mechanism down to room temperature. Multilayer strengthening models historically rely solely on dislocation-based arguments; therefore, consideration of diffusion-based deformation in nanolaminates with low melting temperature components offers improved understanding of multilayer behavior.

Multi-scale in-situ micro-mechanical characterization of Polymer Core Solder Ball (PCSB) coatings for BGA interconnections

“…In this paper, only Room Temperature mechanical properties are investigated whereas PCSBs should sustain load at varying temperature that can be down to -50°c and up to 150°C. Thanks to intense developments in micromechanical testing in the past decade, high and low temperature micropillar compression are now available [49,50]. Also cyclic/fatigue behaviour at the micronscale can be investigated thanks to high frequency micromechanical tests [51].…”

Temperature Dependent Critical Stress for {10-12} Twinning in Magnesium Micropillars at Cryogenic Temperatures

“…The tests were performed with the in situ Alemnis microindenter module (Alemnis AG, Switzerland) previously used at elevated temperature [25] but suitably modified for cryogenic conditions, inside a DSM 962 (Zeiss, Germany) scanning electron microscope (SEM). The main components of the system are reported elsewhere [26][27][28]. A cold finger connected to the sample and tip holders by copper braids is cooled by circulating nitrogen from a 25 L dewar outside the vacuum chamber.…”