Material-process interactions in particle bed 3D printing and the underlying physics

This paper focuses on material-process interactions in particle bed binding. After a classification of particle bed binding techniques currently available for cement-based materials, the most important material-process interactions and their underlying physics are discussed in detail for the selective cement activation (SCA) and the selective paste intrusion technique (SPI). Here, we consider the sub-processes layer application, layer compaction, fluid application, fluid penetration and after printing treatment. We show that, by varying the material and process parameters in these sub-processes, the printing process and the resulting material properties of the printed component, such as compressive strength, durability and dimensional accuracy, can be specifically controlled. Furthermore, we illustrate how these sub-processes can be both understood and described on the basis of the underlying mechanisms and physically based material models.