Micro-scaled Products Development via Microforming

Product miniaturization is a ubiquitously global trend in many industrial clusters such as biomedical device, consumer electronics, communication, aerospace, automotive, and military.

Microforming, the so-called micro-scaled plastic deformation, is to fabricate the parts or part features with the dimensions in submillimeter scale. The process has great potential to become a promising micromanufacturing method for its unique characteristics for fabrication of micro-formed parts [1]. Although a comprehensive macroforming knowledge system to support the design of process, tooling, and the metal forming part has been well established and widely used [2‐6], and the development of microparts by microforming, however, cannot totally be based on the traditional macroforming knowledge and the design and development paradigm of macro-formed parts as the size effect affected deformation behaviors and process performance in microforming are different from the ones in macroforming [7‐9]. In microforming, the material deformation behavior is characterized by a few grains in the deformation zone. Different properties of grains make the deformation behavior inhomogeneous and difficult to predict. In addition, there are interactive effects between workpiece size and microstructure on flow stress, flow behavior, fracture behavior, elastic recovery, and surface roughening, etc. These size effect-related deformation phenomena further affect the performance of microforming system and product quality in terms of deformation load, stability of forming system, defect formation, dimensional accuracy, surface finish, and the mechanical properties of the micro-formed parts. This chapter aims at discussing the size effect-related deformation behaviors and the newly identified phenomena, which will help understand the mechanisms and fundamentals of the size effects in microforming processes.

In the prior studies of microforming from the perspective of size effects, one focus is on the deformation related and the other is on the interfacial friction related.

With the global trend of product miniaturization, the market demands for microparts are increasing tremendously and state-of-the-art micromanufacturing processes for fabrication of microparts thus become critical. Microforming, as one of the micromanufacuring processes, provides a promising approach to fabricating metallic microparts, such as connector pin, miniature screw, microgear, microshaft, chip leadframe, and IC-socket.

Similar to macroforming processes, meso- and micro-scaled plastic deformation or mesoforming and microforming can also have forming defects. Flow-induced defect is a common defect in the metal forming parts fabricated by mesoforming and microforming processes.

Metallic glasses have unique properties of high strength, large elastic strain limit, perfect elastic behavior, and high corrosion resistance. Prior studies have demonstrated some potential and promising applications of metallic glasses in different fields.