Advances in Manufacturing ›› 2023, Vol. 11 ›› Issue (1): 1-20.doi: 10.1007/s40436-022-00414-0

• •    

Size effects on process performance and product quality in progressive microforming of shafted gears revealed by experiment and numerical modeling

Jun-Yuan Zheng1, Hui Liu1, Ming-Wang Fu1,2   

  1. 1. Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China;
    2. Research Institute for Advanced Manufacturing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China
  • 收稿日期:2022-02-10 修回日期:2022-03-29 发布日期:2023-02-16
  • 通讯作者: Ming-Wang Fu,E-mail:mmmwfu@polyu.edu.hk E-mail:mmmwfu@polyu.edu.hk
  • 作者简介:Jun-Yuan Zheng received the M.S. and Ph.D. degrees, both in mechanical engineering from the Hong Kong Polytechnic University (PolyU), Hong Kong, People's Republic of China, in 2018 and 2021, respectively. He is now a postdoctoral fellow in The Aviation Services Research Centre of PolyU. His research interests include microforming, material deformation, and forming process modeling;
    Hui Liu received the M.S. degree in mechanical engineering from the Hong Kong Polytechnic University, Hong Kong, People's Republic of China, in 2021. He is now a Ph.D. candidate at the Department of Mechanical and Automation Engineering, the Chinese University of Hong Kong, Hong Kong, People's Republic of China. His research interests include microforming and additive manufacturing;
    Ming-Wang Fu received his BEng and MEng from the Northwestern Polytechnical University, China, and PhD from National University of Singapore, Singapore. Before he went to Singapore for his career development, he had worked in China as a faculty member and conducted many projects funded by governmental agencies and industries. In 1991 and 1994, he received the honorary awards of Outstanding Young Teacher and Outstanding Teacher from the Ministry of Aeronautic and Astronautic Industries of China and was promoted to Associate and Full Professor via the fast-track promotion scheme in 1992 and 1995, respectively. In 1997, he joined the Singapore Institute of Manufacturing Technology as a Senior Research Engineer. In 2006, he joined The HK Polytechnic University as a faculty member. Prof Fu's research endeavor is more on exploring advanced materials processing and manufacturing, numerical modeling and simulation, damage and fracture, and micro-mechanics to seek an epistemological understanding of the scientific essence behind, advancing knowledge in these areas, and successfully addressing a plethora of challenges and bottleneck issues the areas face. He has secured 12 projects from GRF, ITF and NSFC after 2007 to support his research, including a competitive NSFC Key Project with the funding of RMB 3.0 million. Prof. Fu is sitting in the Editorial Board or as an Associate editor of 18 journals including Int. J. Mach. Tools Manuf., Int. J. of Plasticity, Mater & Design, Int. J. of Damage Mechanics, Int. J. of Mech. Sci., and the editor of Elsevier's Encyclopedia of Materials:Metals and Alloys. He is also serving as a reviewer for many SCI journals, prestigious scientific awards including National Natural Science Award and Scientific Exploration Award (Xplorer Prize) of China, and funding applications. He has published about 240 SCI papers and half of the papers are published in the top 10% SCI journals in corresponding disciplines, 6 monographs and one edited Elsevier's encyclopedia volume published by Springer, Elsevier, CRC Press, etc.

Size effects on process performance and product quality in progressive microforming of shafted gears revealed by experiment and numerical modeling

Jun-Yuan Zheng1, Hui Liu1, Ming-Wang Fu1,2   

  1. 1. Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China;
    2. Research Institute for Advanced Manufacturing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China
  • Received:2022-02-10 Revised:2022-03-29 Published:2023-02-16
  • Supported by:
    The authors would like to acknowledge the funding support to this research from the projects of ZE1W and BBAT from The Hong Kong Polytechnic University, the National Natural Science Foundation of China (NSFC) (Grant No. 51835011), and the General Research Fund (GRF) (Grant No. 15223520).

摘要: As one of the indispensable actuating components in micro-systems, the shafted microgear is in great production demand. Microforming is a manufacturing process to produce microgears to meet the needs. Due to the small geometrical size, there are uncertain process performance and product quality issues in this production process. In this study, the shafted microgears were fabricated in two different scaling factors with four grain sizes using a progressively extrusion-blanking method. To explore the unknown of the process, grain-based modeling was proposed and employed to simulate the entire forming process. The results show that when the grains are large, the anisotropy of single grains has an obvious size effect on the forming behavior and process performance; and the produced geometries and surface quality are worsened; and the deformation load is decreased. Five deformation zones were identified in the microstructures with different hardness and distributions of stress and strain. The simulation by using the proposed model successfully predicted the formation of zones and revealed the inhomogeneous deformation in the forming process. The undesirable geometries of microgears including material unfilling, burr and inclination were observed on the shaft and teeth of gear, and the inclination size is increased obviously with grain size. To avoid the formation of inclination and material unfilling, the punch was redesigned, and a die insert was added to constraint the bottom surface of the gear teeth. The new products had then the better forming quality.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-022-00414-0

关键词: Microforming, Microprocess performance, Microforming quality, Size effect affected deformation behavior, Die design optimization

Abstract: As one of the indispensable actuating components in micro-systems, the shafted microgear is in great production demand. Microforming is a manufacturing process to produce microgears to meet the needs. Due to the small geometrical size, there are uncertain process performance and product quality issues in this production process. In this study, the shafted microgears were fabricated in two different scaling factors with four grain sizes using a progressively extrusion-blanking method. To explore the unknown of the process, grain-based modeling was proposed and employed to simulate the entire forming process. The results show that when the grains are large, the anisotropy of single grains has an obvious size effect on the forming behavior and process performance; and the produced geometries and surface quality are worsened; and the deformation load is decreased. Five deformation zones were identified in the microstructures with different hardness and distributions of stress and strain. The simulation by using the proposed model successfully predicted the formation of zones and revealed the inhomogeneous deformation in the forming process. The undesirable geometries of microgears including material unfilling, burr and inclination were observed on the shaft and teeth of gear, and the inclination size is increased obviously with grain size. To avoid the formation of inclination and material unfilling, the punch was redesigned, and a die insert was added to constraint the bottom surface of the gear teeth. The new products had then the better forming quality.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-022-00414-0

Key words: Microforming, Microprocess performance, Microforming quality, Size effect affected deformation behavior, Die design optimization