報告題目: Progressive and compound forming of bulk micro-scaled by using sheet metals
報告人簡介: 傅銘旺，香港理工大學機械工程學院教授，塑性加工領域國際知名專家，主要研究綜合產品設計與工藝研發，金屬成形與模具設計，微細精密零部件的製造及先進材料微細成形加工。擔任Int. J. Plasticity、Mater. Design、Int. J. Damage Mech.、Int. J. Adv. Manuf. Tech.、中國機械工程-英文版等多個SCI權威期刊編委，也是多個SCI期刊、重大獎項評比及項目課題申報的特邀評審人。現已在IJP、IJMTM、JMPT等頂級/權威期刊發表SCI論文160餘篇，其中塑性領域TOP1期刊IJP 14篇，出版英語專著5部，多篇學術論文被著名的國際微製造會議授予“最佳論文獎”以及多篇學術論文被Web of Science TM評為“SCI高被引論文”。
The most critical issues in microforming technologies are tailoring the desirable product quality and ensuring the high productivity from application perspective. To realize batch micromanufacturing of the flanged microparts, an efficient progressive microforming method is proposed by using an integrated hole flanging-ironing process. In this process, size effect and its affected deformation behavior, forming quality and ductile fracture of the micropart are still not well known. In addition, the ductile fracture behavior of work material is induced by the accumulated degradation of material stiffness when plastic deformation level reaches a certain limit, which is liable to occur due to the accumulated deformation in progressive flanging-ironing process. The unique accumulative deformation behavior and its affected ductile fracture is closely related to the forming quality and defect formation in the progressive microforming. This study thus aims at addressing these issues in terms of dimensional accuracy, accumulative deformation, defect formation and ductile fracture based on an unequal-thickness flanged micropart produced by the developed progressive microforming system in which shearing, hole flanging-ironing and blanking operations are realized progressively. The experimental and simulative results reveal that the dimensional accuracy of the flanged micropart is aggravated with the increasing grain size due to the coupled effect of free surface roughening and interfacial friction. The fracture phenomenon at the flanged tips show the increasing trend with the decreasing number of grains over the thickness of workpiece. Through realization and examination of the developed progressive microforming system and the finished microparts, the progressive micro flanging-ironing process is proven to be promising and efficient for mass micromanufacturing of micro flanged parts.