A Methodology to Characterize Structurally the Bonding between Two Parts Made of FDM-3D Printed Dissimilar Materials

Abstract

Fused Deposition Modelling (FDM) is a common technique used when rapid prototyping is needed to perform a preliminary evaluation of the suitability of a part. For this purpose, several materials, as PLA, ABS, PET-G and others, are easily available in the market along with a wide range of commercial 3D printers at affordable prices. Prototypes manufactured under this technique are usually made of a single material and, for most of the applications, it is enough to fulfill the required specifications. However, the increasing demand for the manufacturing of parts made of more than one material suggests that prototyping via FDM using two dissimilar materials should be assessed to assure that such technique is still acceptable to perform a preliminary evaluation of a part. For this purpose, a methodology using a commercial FDM 3D printer is proposed to characterize the flexural and shear bonding behavior of two dissimilar materials. This methodology implements four steps: The selection of the applicable UNE standards as main reference, the design and manufacture of the test specimens based on these standards, the execution of the structural tests to characterize the behavior of those specimens and the analysis of the test data along with the conclusions. This methodology has been validated using ABS and PLA as base materials. The coherence and accuracy of the results obtained from this specific case substantiate that it is a valid methodology to evaluate the structural behavior of the bonding of two dissimilar materials, beyond PLA and ABS, using commercial and affordable off-the-shelf 3D printers.