Statistical Analysis of the Tensile Properties of Various Polymers Processed through 3D Printing Introduction Additive Manufacturing is a new processing method developed for creating a 3-Dimensional object by adding layer upon layer of material whether it is a polymer, metal, concrete or even human tissue. The main techniques used in Additive Manufacturing are: SLA (Stereolithography) FDM (Fused deposition modeling) MJM (Multi-jet modeling) 3DP (Three dimensional printing) SLS (Selective laser sintering) The polymers studied in this project are: PLA (Polylactic acid) ABS (Acrylonitrile butadiene styrene) Bio-ABS They are processed using the FDM technique on a Lulzbot Mini following the ASTM (American Society for Testing and Materials) standards. Methodology 1. Designing the Test Specimen in CAD In order to test the polymers for the tensile properties, the test specimen was designed in Solidworks following the ASTM standards for tensile testing polymers. The CAD file was then converted into STL and sliced to create G-code so that the printer could print the mechanical testing specimens Conclusions Using 3-D printing, three different polymers were successfully processed and tested for mechanical properties. The PLA exhibits highest strengths among three polymers under the given processing and test conditions. ABS and Bio-ABS show very comparable mechanical properties. The effect of fill density on mechanical properties is clearly shown in that both modulus and strength increased linearly with density. Results 2. Printing & Testing the Tensile Specimens After the CAD file is converted from STL to G-Code the specimens are printed out of each material using the Lulzbot Mini using the same conditions for each print job After all of the specimens were printed they were tested on the Instron APEX 60UD and pulled until fracture Figure 7: Stress-Strain Curves of ABS Figure 8: Effect of Fill Density on Strength Figure 9: Effect of Fill Density on Modulus Figure 1: The ASTM Standard and A 3-D render of the test specimen Figure 2: The specimens being 3-D printed Acknowledgements: This work was supported primarily by the Engineering Research Center Program of the National Science Foundation and the Department of Energy under NSF Award Number EEC and the CURENT Industry Partnership Program. 1. Mechanical Properties of Different Polymers Tensile testing was performed on the Instron APEX 60UD with a strain rate of 5.6x10 -4 /sec. The data was analyzed using Microsoft Excel and Origin programs. 2. Effect of Fill Density on Mechanical Properties ABS test specimens were made with varying fill densities of 25, 60, and 100% and then tested to investigate the effect of fill density on Elastic Modulus and Ultimate Strength for ABS. Luke Buckner, Oak Ridge High School [Mentors: Peijun Hou, Yuan Li, Zane Palmer, Hahn Choo, University of Tennessee] Figure 3: The specimen tested on the Instron Figure 5: Modulus of Elasticity for the 3 Polymers Figure 4: Stress-Strain Curves for the 3 Polymers Figure 6: Ultimate Strength and Maximum Elongation for the 3 Polymers Objectives To study each polymer for their mechanical (tensile) properties To study the effect of fill density on elastic modulus and ultimate strength Figure 7 Figure 8 Figure 9