Further experiments and modeling for microscale compression molding of metals at elevated temperatures

Replication of metallic high-aspect-ratio microscale structures (HARMS) by compression molding has been demonstrated recently. Molding replication of metallic HARMS can potentially lead to low-cost fabrication of a wide variety of metal-based microdevices. Understanding the mechanics of metal micromolding is critical for assessing the capabilities and limitations of this replication technique. This paper presents results of instrumented micromolding of Al. Measured molding response was rationalized with companion high-temperature tensile testing of Al using a simple mechanics model of the micromolding process. The present results suggest that resisting pressure on the mold insert during micromolding is governed primarily by the yield stress of the molded metal at the molding temperature and a frictional traction on the sides of the insert. The influence of strain rate is also considered.