Freedom of design, mass customisation, waste minimisation and the ability to manufacture complex structures, as well as fast prototyping, are the main benefits of additive manufacturing (AM) or 3D printing. A comprehensive review of the main 3D printing methods, materials and their development in trending applications was carried out. In particular, the revolutionary applications of AM in biomedical, aerospace, buildings and protective structures were discussed. The current state of materials development, including metal alloys, polymer composites, ceramics and concrete, was presented. In addition, this paper discussed the main processing challenges with void formation, anisotropic behaviour, the limitation of computer design and layer-by-layer appearance. Overall, this paper gives an overview of 3D printing, including a survey on its benefits and drawbacks as a benchmark for future research and development.

Additive manufacturing (3D printing): A review of materials, methods, applications and challenges

Additive manufacturing (AM) alias 3D printing translates computer-aided design (CAD) virtual 3D models into physical objects. By digital slicing of CAD, 3D scan, or tomography data, AM builds objects layer by layer without the need for molds or machining. AM enables decentralized fabrication of customized objects on demand by exploiting digital information storage and retrieval via the Internet. The ongoing transition from rapid prototyping to rapid manufacturing prompts new challenges for mechanical engineers and materials scientists alike. Because polymers are by far the most utilized class of materials for AM, this Review focuses on polymer processing and the development of polymers and advanced polymer systems specifically for AM. AM techniques covered include vat photopolymerization (stereolithography), powder bed fusion (SLS), material and binder jetting (inkjet and aerosol 3D printing), sheet lamination (LOM), extrusion (FDM, 3D dispensing, 3D fiber deposition, and 3D plotting), and 3D bioprinting....

Polymers for 3D Printing and Customized Additive Manufacturing

Along with extensive research on the three-dimensional (3D) printing of polymers and metals, 3D printing of ceramics is now the latest trend to come under the spotlight. The ability to fabricate ceramic components of arbitrarily complex shapes has been extremely challenging without 3D printing. This review focuses on the latest advances in the 3D printing of ceramics and presents the historical origins and evolution of each related technique. The main technical aspects, including feedstock properties, process control, post-treatments and energy source–material interactions, are also discussed. The technical challenges and advice about how to address these are presented. Comparisons are made between the techniques to facilitate the selection of the best ones in practical use. In addition, representative applications of the 3D printing of various types of ceramics are surveyed. Future directions are pointed out on the advancement on materials and forming mechanism for the fabrication of high-performance ceramic components.

3D printing of ceramics: A review

https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=924709

3D printing using concrete extrusion: A roadmap for research

Additive manufacturing (AM) is a technology which has the potential not only to change the way of conventional industrial manufacturing processes, adding material instead of subtracting, but also to create entirely new production and business strategies. Since about three decades, AM technologies have been used to fabricate prototypes or models mostly from polymeric or metallic materials. Recently, products have been introduced into the market that cannot be produced in another way than additively. Ceramic materials are, however, not easy to process by AM technologies, as their processing requirements (in terms of feedstock and/or sintering) are very challenging. On the other hand, it can be expected that AM technologies, once successful, will have an extraordinary impact on the industrial production of ceramic components and, moreover, will open for ceramics new uses and new markets.

Additive Manufacturing of Ceramics: Issues, Potentialities, and Opportunities

Building components for an outpost on the Lunar soil by means of a novel 3D printing technology

In recent years rapid prototyping (a.k.a. 3D-Printing) technologies gained growing interest in the architecture community for their promise to allow direct construction of buildings with virtually any shape. Some of these technologies have the capability to agglomerate inert materials like sand using a special “ink”. This feature is especially attractive for the space community, for in-situ resources utilization related to manned space exploration. In November 2009 the European Space Agency awarded a General Study Programme contract to an industrial consortium formed by Alta SpA, Monolite Ltd., Foster+Partners and Scuola Superiore Sant‟Anna. The objective of the study is to assess the concept of 3D printing technology as a potential way to build habitat on the Moon using lunar regolith. The consortium merges knowledge in space technology development, 3-D printing at building scale, complex architectural design, and robotics. In particular, Monolite Ltd. holds the rights for the patented D_SHAPE 3D-printing technology which is, among several different rapid prototyping systems, one of those which is closer to enable full scale construction of buildings. In the initial phase of the study, the physical and chemical characteristics of lunar regolith and terrestrial regolith simulants were assessed with respect to the working principles of D_SHAPE. This work also led to the selection of a novel lunar regolith simulant, made using the ashes of the Bolsena volcano in Italy, which almost exactly reproduces the characteristics of the well-known JSC-1A simulant produced in the US. Tests in air and under vacuum were performed in order to demonstrate that the reticulation process takes place using the regolith simulant. The vacuum tests also showed that evaporation or freezing of the ink can be prevented by adopting a proper injection method. In parallel, the general requirements of a Moon outpost were specified, and a preliminary design of the habitat is underway at Foster+Partners. Based on such design, a section of the outpost wall will be selected and manufactured at full scale using the D_SHAPE printer and the selected regolith simulant. Test pieces of the reticulated “concrete” are going to be manufactured in parallel and will be subject to testing of mechanical properties. Finally, based on the results of the study, the guidelines for future spatialization and automation of the printer and for design and 3D printing of the outpost will be drawn. The study conclusion is currently foreseen by Spring 2011.

Enrico Dini

Papers

Building components for an outpost on the Lunar soil by means of a novel 3D printing technology

3D printing technology for a moon outpost exploiting lunar soil

Review of binder jetting 3D printing in the construction industry

Large Scale 3D Printing: from Deep Sea to the Moon

Digital Fabrication with Cement-Based Materials: Process Classification and Case Studies