Review on progressive microforming of bulk metal parts directly using sheet metals (Keynote Paper)

Due to the ubiquitous trend of product miniaturization, energy saving and weight reduction, micro/meso-scale parts have been widely used in many industrial clustersMicromanufacturing processes for production of such micro/meso-scale parts are thus critically neededMicroforming, as one of these micro manufacturing processes, is a promising process and thus got many explorations and researchesCompared with the research on size effect affected deformation behaviours, less attention has been paid to the process development for mass production of micro-partsThe product quality and fabrication productivity of micro-parts depend on the involved process chainTo address the difficulty in handling and transporting of the micro-sized workpiece, development of a progressive microforming process for directly fabricating bulk micro-parts using sheet metals seems quite promising as it avoids or facilitates billet handling, transportation, positioning, and ejection in the process chainIn this paper, an intensive review on the latest development of progressive microforming technologies is presentedFirst of all, the paper summarizes the characteristic of progressive microforming directly using sheet metalThe size effect-affected deformation behaviour and the dimensional accuracy, deformation load, ductile fracture, and the surface finish of the microformed parts by progressive microforming using sheet metals are then presentedFinally, some research issues from the implementation of mass production perspective are also discussed.