Additive manufacturing of ceramic components

Abstract

Aiming 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.