Using 3D printed DMLS mesoscale structures to control the elastic modulus of a material

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Terail Clonts (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/
Advisor
Martin Tanaka

Abstract: Direct Metal Laser Sintering (DMLS) is an additive manufacturing (AM) technique that uses a laser to fuse metallic powders by sintering the powder layer by layer. This study used a DMLS machine to print 316L stainless steel parts with varying internal geometries in order to manipulate the elastic modulus of a mesoscale material. Parameters may be established that allow the elastic modulus of a part to be controlled through the mesoscale structure of the material. The ability to control the stiffness of a part is applicable in the creation of orthopedic implants in order to reduce stress shielding. Specimens with differing mesoscale configurations were designed using 3D CAD software and created with DMLS. Uniaxial tensile testing was performed on each specimen in order to determine the elastic modulus. The solid specimen variant had a greater modulus than all variants containing mesoscale structures, and roughly one fourth the modulus of human bone. The elastic modulus of the mesoscale structures were roughly 1.9 to 3.7 times greater than that of the solid variant. As expected, the Poisson’s ratio for the re-entrant hexagonal x-axis-oriented specimen was negative because of the nature of the structure, but this was the only structure that exhibited this behavior. Overall, it was determined that the elastic modulus of a 3D metal part can be controlled using mesoscale design.

Additional Information

Publication
Thesis
Language: English
Date: 2021
Keywords
DMLS, Mesoscale, Stress Shielding
Subjects
Laser sintering
Three-dimensional printing
Elasticity

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