Title: Development of burnishing process using free-ball tools for surface modification and improvement of corrosion resistance of inner wall of water channels of die-casting moulds
Authors: Masato Okada; Reyu Yamamoto; Yuji Kobayashi; Yuta Saito
Addresses: Faculty of Engineering, University of Fukui, 3-9-1, Bunkyo, Fukui 910-8507, Japan ' Graduate School of Mechanical Engineering, University of Fukui, 3-9-1, Bunkyo, Fukui 910-8507, Japan ' Sintokogio, Ltd., 180-1, Komaki, Ohgi-cho, Toyokawa, Aichi 441-1205, Japan ' Sintokogio, Ltd., 180-1, Komaki, Ohgi-cho, Toyokawa, Aichi 441-1205, Japan
Abstract: A burnishing process that use free-ball tools on the inner surface of a drilled hole was developed to prevent surface cracking and corrosion in the cooling water channels of die-casting moulds. In the developed burnishing process, a pressure bar with a hammering mechanism is used to apply impact forces to multiple hard balls placed in the target hole. The resulting compressive forced achieve surface modification at multiple contact points between the free-ball tools and inner surface of the target hole. These contact points are changed by stirring the ball tools, thereby applying a burnishing effect to the entire inner surface of the hole. Moreover, zinc powder is interposed between the free-ball tools and target surface, where it adheres to the target surface and improves the corrosion resistance.
Keywords: surface modification; corrosion-resistance treatment; burnishing process; free-ball tools; surface profile; hole inner surface; hardened die steel; water channels; die-casting mould.
International Journal of Abrasive Technology, 2024 Vol.12 No.2, pp.106 - 127
Received: 03 Aug 2023
Accepted: 02 Jan 2024
Published online: 20 Aug 2024 *