Many people make a lot of assumptions about the material properties of 3D printed parts based on the material that the printer uses and the way that the additive manufacturing process is implemented. For example, I’ve often heard people mention that 3D printed parts are weak along the axis normal to the build plate (usually the Z axis). But weak in what way? Is it a torsional weakness, a shear weakness, or a tensile weakness? And even with that knowledge, which material or printer will produce the best results for a specific application? I have found very few resources that share the results of various material properties of 3D printed parts across different printers and orientations (although if you know of some, please let me know!). The material properties of base materials used in 3D printing, like ABS, PLA, and Nylon are widely accessible, but not often compared to their printed counterparts. Testing the material properties of 3D printed parts is extremely valuable because it will inform and guide the process of designing efficient parts. Over the course of the next few weeks, I’ll be testing material samples across a variety of different materials and printers, including the Stratasys Dimension 1200es, the MakerBot Replicator 2, the MakerBot Replicator 2X, the Form 2, and the MarkForged printer.
The first series of tests I’ll be running will be tensile tests across different orientations on the printer and across a few different printers. I’ll be putting test samples in a testing machine and loading them in tension, essentially pulling them until they fail. By performing these tests on parts created on different axes (for example, printing the same part with its longest side printed in line with the X, Y, or Z axes of the printer), we can develop an understanding of a lot of important mechanical properties and how they are affected by part orientation, printer, and material. From running a tensile test, we can determine the stress and strain on the part, the modulus of elasticity, the tensile strength, and the energy a part absorbs before failure. This information will let us determine the stiffness of the part, how much force it can take for a given area, and how the part behaves before failure. We can account for these properties in our design and orientation choices to make them stronger for their specific application.
I’ll be running these tests over the next few weeks, so if there is any specific data you’d be interested in seeing, please let me know! Additionally, if there are any tests you would like me to run on 3D printed parts, please suggest in the comments!