The Use of Multiple Materials in Additive Manufacturing
Almost since the very beginning, experimenters have tried to use more than one material in Additive Manufacturing machines. In fact, multiple materials are a fundamental benefit to how some AM technologies work. The Laminated Object Manufacturing (LOM) pr
- PDF / 205,934 Bytes
- 14 Pages / 439.37 x 666.142 pts Page_size
- 3 Downloads / 301 Views
The Use of Multiple Materials in Additive Manufacturing
17.1
Introduction
Almost since the very beginning, experimenters have tried to use more than one material in Additive Manufacturing machines. In fact, multiple materials are a fundamental benefit to how some AM technologies work. The Laminated Object Manufacturing (LOM) process, for example, was one of the earliest AM technologies developed and required that sheet material (paper) be combined with a resin to bond the sheets together to form a composite object of paper and resin. Many vendors and researchers have added further materials to the single-material AM technologies in order to enhance the basic process, either to optimize the process or to improve the properties of the final part in some way. This chapter will explore the different AM processes with respect to how multiple materials have been included in them. It will go on to discuss the different ways in which materials can be combined as an attempt to classify the various types of multiple material structures. Key research milestones will be presented with an aim to understand the benefits of multiple materials in AM for product development and how this technology may develop in the future.
17.2
Multiple Material Approaches
Multiple materials can be introduced to an AM process according to a variety of different strategies, for example: – Two or more discrete materials can be placed next to each other. The interface between the materials can be such that they are either simply in contact with each other or where they are bonded together in some way. Two discrete materials are often used when generating supports, such as in the FDM process, where supports may be of a different material to the part and can, therefore, be easily removed once the build has been completed. I. Gibson, D.W. Rosen, and B. Stucker, Additive Manufacturing Technologies, DOI 10.1007/978-1-4419-1120-9_17, # Springer ScienceþBusiness Media, LLC 2010
423
424
17 The Use of Multiple Materials in Additive Manufacturing
– A material can be processed in such a way that there is porosity in some segments or throughout the whole of the resulting part. It is quite common for powder based systems to display such porosity. This porosity can allow the use of a liquefied secondary material for infiltration. In some processes, the porosity may be varied in different regions (for example, by varying the laser power in the SLS Powder Bed Fusion process) so that the ratio of parent material to infiltrant can also be varied throughout the part. Furthermore, infiltration may occur during the AM process at the layer level rather than merely as a post-AM process. The binders used in the 3D Printing processes are an example of this approach. 3D Printed parts often require an additional post-build infiltration to further strengthen the part, adding a third material component into the structure. – Feed material can be presented to the AM process as a blend of two or more different materials. In some cases, it may be possible to vary the rati
Data Loading...
