Many industries—from equipment manufacturers to automotive, medical, and ceramic industries—have adopted additive manufacturing (AM). What is additive manufacturing? According to SME, “The term additive manufacturing refers to a collection of technologies where materials are selectively accumulated to build, grow, or increase the mass of an object layer-by-layer until a three-dimensional object conforms to its digital model. Objects that are manufactured additively can be found throughout the product life cycle, from pre-production (e.g., rapid prototyping) to full-scale production (e.g., rapid manufacturing), in addition to tooling applications and post-production customization.”¹

As a result of his development and the groundbreaking patent work back in 1980s, Charles W. Hull is credited as the inventor of additive manufacturing. Since the early days of this process development, there has been significant impact. Writing in the article, “5 Manufacturing Trends to Watch in 2018,” the Association of Equipment Manufacturers highlights a key trend:

Companies have seen the value of employing additive processes for prototyping, tooling and even final production applications to help positively impact time and cost efficiencies. For example, heavy equipment manufacturers produce machinery with product lifespans measured in decades. As a result, they are forced to invest heavily in maintaining large inventories of spare parts, ready for when a customer places an order. Many manufacturers are looking into using 3D printing to making a replacement part without having the inventory in place, saving them the significant overhead costs of warehouse space. Furthermore, the production of molds, jigs and fixtures used in the mass production of heavy equipment presents an even greater opportunity to leverage additive manufacturing to increase operational efficiency.²

In addition to the widening application of additive manufacturing (sometimes referred to as 3D printing), the knowledge base is also growing on the topic. An additive manufacturing certification credential is now available from SME, for example.³ The credential aligns to the Additive Manufacturing Body of Knowledge compiled by the Milwaukee School of Engineering (MSOE), Tooling U-SME, America Makes, the National Coalition of Advanced Technology Centers (NCATC), and Technician Education in Additive Manufacturing & Materials (TEAMM).

Research Focus Areas

With this foundation and growing knowledge base, what research conclusions are related to additive manufacturing for the ceramic industry? Let me summarize some of the key research in the application of AM in ceramic processes.

In the area of materials investigation, Li Yang and Hadi Miyanaji of the department of Industrial Engineering at the University of Louisville, state:

In terms of ceramic material availability, the existing AM technologies already demonstrated excellent material compatibility. New materials such as boron carbide (B₄C) and titanium boride (TiB₂) might also possess promising potentials for AM adoption due to their potentials in high value-added ceramic armor applications. In addition, the capability of AM in applying materials on a voxel-by-voxel basis could be potentially utilized for the doping of ceramics, which is an important method in altering the material characteristics of ceramics.⁴

As to AM methods reported in the literature to shape ceramic components, J. Deckers, J. Vleugels, and J.-P. Kruth, writing in the Journal of Ceramic Science and Technology, conclude:

It has been demonstrated that, especially for AM of ceramics, the multi-step (indirect) AM processes are more appropriate to shape different types of ceramics, while single-step (direct) AM processes can produce parts more rapidly. Further, it can be concluded that ceramic parts that have no cracks or large pores have mechanical properties close to those of conventionally produced ceramics. Such parts can be fabricated by optimizing the AM process parameters or performing extra densification steps after the AM process. In order to produce crack- and pore-free ceramics with AM, it is also advisable to incorporate colloidal processing techniques into the AM process.⁵

Regarding additive manufacturing related to glass materials, research has also been promising. One example relates to optically transparent glass. John Klein, Michael Stern, Giorgia Franchin, et. al., have demonstrated a “fully functional material extrusion printer for optically transparent glass.” The printer “is composed of scalable modular elements able to operate at the high temperatures required to process glass from a molten state to an annealed product.”⁶

In summary, research continues to show growing benefits to the application of AM related to ceramic manufacturing. Stating that this technology is a game changer, McKinsey consultants Jörg Bromberger and Richard Kelly conclude that, “the number of materials that AM can handle is constantly expanding. A wide range of new plastics has been developed, along with processes and machines for printing with ceramics, glass, paper, wood, cement, graphene, and even living cells. Applications are now available in industries ranging from aerospace to automobiles, from consumer goods (including food) to health care (where artificial human tissue can be produced using AM).”⁷