Plasma Nitriding-Assisted Printing of Stainless Steel Punches for Micro-piercing Process

作     者：Tatsuhiko Aizawa Tomomi Shiratori 

作者机构：Department of Engineering and Design Shibaura Institute of Technology 3-9-14 Shibaura Minato-City Tokyo 108-8548 Japan R & D Center Komatsu Seiki Kosakusho Co. Ltd. Shiga-Kuwahara Ohaza Suwa-City Nagano 942-2 Japan 

出 版 物：《Journal of Mechanics Engineering and Automation》 (机械工程与自动化（英文版）)

年 卷 期：2017年第7卷第1期

页      面：1-11页

学科分类：08[工学] 0802[工学-机械工程] 

主　　题：Plasma printing ink-jet printing plasma nitriding sand-blasting micro-piercing stainless steel punch. 

摘      要：MEMS （micro-electric-mechanical-system） required for miniature, thin mechanical parts as a structural member; e.g., the miniature pumping system consisted of ten to twelve thin metallic plates before joining. At present, those thin shaped sheets were fabricated by the chemical etching. Their geometric inaccuracy as well as long leading time often became an engineering issue. Micro-piercing process was expected to make mass production of thin sheet products with complex and accurate geometry for much shorter leading time once the die for this micro-piercing was built in. In the present paper, a new plasma nitriding-assisted printing was proposed as an automatic production line to fabricate the micro-piercing punch. After preparation of CAD-data of the punch head, its two dimensional geometry was ink-jet printed directly on the AISI420 stainless steel die-substrate. The unprinted surface area was only plasma nitrided at 693 K for 14.4 ks to transform this two dimensional micro-pattern to the three dimensional hardness distribution in the AISI420 substrate. Through the mechanical removal of ink-jet printed area, the flat punch head with sharp edge comers was fabricated in much shorter duration time than the end-milling. SEM-EDX, surface profiling measurement as well as micro-hardness testing were employed to describe each step in the above plasma printing. The thin MEMS stainless steel part with a micro-pendulum as well as three S-letter shaped springs was taken for an example to describe this automatic production procedure of plasma printing from the CAD data mining to the micro-piercing punch finishing.