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

M.W Fu,B Meng,Y Qin,J Lin,F Vollertsen,S J Yuan,T A Dean

doi:10.1051/matecconf/20152109001

Abstract

Due to the ubiquitous trend of product miniaturization, energy saving and weight reduction, micro/meso-scale parts have been widely used in many industrial clusters. Micromanufacturing processes for production of such micro/meso-scale parts are thus critically needed. Microforming, as one of these micro manufacturing processes, is a promising process and thus got many explorations and researches. Compared with the research on size effect affected deformation behaviours, less attention has been paid to the process development for mass production of micro-parts. The product quality and fabrication productivity of micro-parts depend on the involved process chain. To 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 chain. In this paper, an intensive review on the latest development of progressive microforming technologies is presented. First of all, the paper summarizes the characteristic of progressive microforming directly using sheet metal. The 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 presented. Finally, some research issues from the implementation of mass production perspective are also discussed.

Highlights

Compared with the research on size effect affected deformation behaviours, less attention has been paid to the process development for mass production of micro-parts
The product quality and fabrication productivity of micro-parts depend on the involved process chain
Fu and Chan [4, 5] further examined the feasibility of this process to fabricate the meso- and micro-scaled parts by directly using sheet metal, and identified its characteristics via scaling down the part size and using the materials with different grain sizes

Summary

Introduction

Whereas the second approach can address the common issues such as the adhesive forces induced by surface tension, van der Waals-force, and the electrostatic interaction between workpiece and handling tools in microforming process. To explore this process, Hirota [3] extruded micro-billet via pressing the sheet material in thickness direction. Fu and Chan [4, 5] further examined the feasibility of this process to fabricate the meso- and micro-scaled parts by directly using sheet metal, and identified its characteristics via scaling down the part size and using the materials with different grain sizes. A panorama in terms of process realization and product quality control is provided to facilitate the design and development of microparts by using this unique microforming process, and further to advance this promising microforming process for mass production of micro/meso parts for different industrial clusters

Characteristic of progressive microforming

Deformation behaviour and ductile fracture

Conclusions