A net shape process for metallic microcomponent fabrication using Al and Cu micro/nano powders

This paper presents a new fabrication process for producing micro Al-based alloy components. The process is based on micro powder injection moulding technology, while the micromoulds are produced using MEMS technology. The process involves (1) fabrication of PDMS micromoulds from SU-8 masters, which are produced using a UV photolithography process; (2) making metallic paste by mixing 80 wt% of ultrafine Al (2.5 µm in average) powder, 5 wt% of Cu nanopowder (less than 60 nm), and 15 wt% of adhesive binder in about 30 ml of acetone; (3) mould filling with metallic paste and demoulding; and (4) sintering of the moulded component in an Ar atmosphere. The proposed process has been used to sinter Al–Cu powder microcomponents successfully without the help of either high pressure compression or mixing Mg with the Al powder. This research proposes a new approach to fabricate 3D micro metallic components to meet the needs in applications where metal, rather than silicon, microcomponents are required.