Effect of cold-work on the Hall–Petch breakdown in copper based micro-components
Wah, Chua Beng
Jarfors, Anders E.W.
Date of Issue2014-10-27
School of Mechanical and Aerospace Engineering
Singapore Institute of Manufacturing Technology
Effects of substructural dimensions on the mechanical properties of micro-pins produced by an open-die micro-extrusion/forging process were studied. Micro-pins of diameter 0.3 mm were manufactured from copper strips, having different initial grain sizes. Micro-compression tests on the micro-pins revealed no significant size effect, even if the number of grains over the diameter of the micro-pins falls below its critical value. However, relaxation of the as-formed substructure using recovery annealing led to a surprising drop in the flow stress of the micro-pins. This was explained and attributed to the number of subgrains over the diameter of the micro-pins, showing the important role of subgrains rather than grains in determining the mechanical properties.
Mechanics of Materials
© 2014 Elsevier Ltd. This is the author created version of a work that has been peer reviewed and accepted for publication by Mechanics of Materials, Elsevier Ltd. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.mechmat.2014.10.003].