Vol.11 No.2 2018

シンセシオロジー 報告−81−Synthesiology Vol.11 No.2 pp.81–93(Jun. 2018)1 IntroductionBecause of their unique and excellent material properties, ceramics are often used as key parts in many advanced products and systems in a variety of fields including manufacturing, energy, environments, IT, electronics, optics, bio-technologies, and transportation. It is also noteworthy that Japanese ceramic industries have maintained the world’s highest-level manufacturing technologies, which have brought about almost a half of the global market share of ceramic-related products, thanks to their incessant eorts for technological innovation.Ceramic manufacturing process has been composed of several miscellaneous steps including powder preparation, mold making, granulation, forming, dewaxing, sintering, machining, nishing, etc. (Fig. 1, top). In addition, some of the steps such as granulation, dewaxing and sintering require a great deal of thermal energy, indicating higher ratios of labor and energy expenditures to the total production cost in comparison with those of other materials. As a result, production from countries of lower labor and energy costs has been gradually increasing in recent years, along with their progress of manufacturing technologies. To maintain and consolidate the technological superiority and international competitiveness of Japan’s ceramic industry, it is now crucially required to develop innovative manufacturing technologies which enable us to produce creative and novel products of high value. For this purpose, a national R&D project “High-Value Added Ceramic Products Manufacturing Technologies (HCMT)” has been initiated since 2014 in the CSTI, SIP, “Innovative design/manufacturing technologies” program of the government of Japan.[1]-[3] The HCMT project intends to integrate the above-stated miscellaneous steps of manufacturing process into the two key technologies, “additive manufacturing (AM)” and “hybrid coating (HC)” (Fig. 1, middle), which bring about many advantages in terms of production process as well as product performance. AM realizes complex-shaping of ceramic products and reduces their lead-times as will be described later, while HC provides better surface modification of products and enhances their functionality and durability,[4] strengthening the international Tatsuki OHJIAiming for innovative ceramic manufacturing technologies which enable creative and novel products, a national R&D project “High-Value Added Ceramic Products Manufacturing Technologies (HCMT)” has been initiated since 2014 as part of the Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), “Innovative design/manufacturing technologies” program in Japan. The project deals with two key technologies: additive manufacturing (AM) for realizing complex-shaped ceramic products and reducing their lead-times, and hybrid coating on 3D bodies for enhancing their functionality and durability. Following an overview of this project and a brief description on the general status of AM technologies, this article focuses on the R&D strategies and the latest achievements on AM of ceramics in this project. Among a variety of AM approaches, we employ two AM technologies for making ceramic green bodies; powder layer manufacturing (powder bed fusion or indirect selective laser sintering) and slurry layer manufacturing (vat photo-polymerization or stereolithography), because of their dimensional accuracy, shape-flexibility, density-adjustability, etc. The former is a dry forming process, and is suitable for large/porous components, while the latter is a wet one, being good for small/dense parts. In addition, intensive research efforts are being devoted to ceramic laser sintering (direct selective laser sintering) which enables concurrent forming and sintering (saving post-sintering-process). This paper describes several 3D prototype models produced for various application targets using the developed AM technologies, which are never attainable with conventional methods. The current issues and future perspective for AM of ceramics will be addressed and discussed as well.Keywords:Additive manufacturing, ceramics, components, powder, slurry, powder bed fusion, stereolithography, laser sintering, ceramic industryFellow, AIST 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan E-mail: Original manuscript received July 20, 2017, Revisions received January 30, 2018, Accepted February 3, 2018Additive manufacturing of ceramic components—Towards innovation of ceramic industry—

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