Scaling the response of microscale compression molding of elemental Cu in the presence of dynamic recrystallization

Replication of metallic high-aspect-ratio microscale structures by direct compression molding is a promising microfabrication technique. In this paper, the micromolding response of elemental Cu is measured as a function of molding temperature. Companion tensile testing of macroscale Cu specimens was carried out at the corresponding molding temperatures. Microstructures of tensile tested macroscale Cu specimens and molded Cu specimens were characterized by combining focused ion beam (FIB) sectioning and imaging with ion-induced secondary electrons (ISEs). At all temperatures tested, measured tensile stress–strain curves for Cu show clear evidence for the occurrence of dynamic recrystallization (DRX) within macroscale tensile specimens. Additional FIB sectioning and imaging with ISEs of molded Cu specimens provide microstructural evidence for the occurrence of DRX during molding. The present results show that, even in the presence of DRX, an appropriate one-parameter scaling continues to reduce the molding response to a universal function independent of the molding temperature.