Weld formation during material extrusion additive manufacturing

Published

August 11, 2017

Author(s)

Jonathan E. Seppala, Seung Hoon Han, Kaitlyn E. Hillgartner, Chelsea S. Davis, Kalman D. Migler

Abstract

Material extrusion (ME) is a layer-by-layer additive manufacturing process that is now used in personal and commercial production where prototyping and customization are required. However, parts produced from ME frequently exhibit poor mechanical performance relative to those from traditional means; moreover, fundamental knowledge of the factors leading to development of inter-layer strength in this highly non-isothermal process is limited. In this work, we seek to understand the development of inter-layer weld strength from the perspective of polymer interdiffusion under conditions of rapidly changing mobility. Our framework centers around three interrelated components: in-situ thermal measurements (via infrared imaging), temperature dependent molecular processes (via rheology), and mechanical testing (via mode III fracture). We develop the concept of an equivalent isothermal weld time and test its relationship to fracture energy. The results of these analysis provide a basis for optimizing inter-layer strength, the limitations of the ME process, and guide development of new materials.

Citation

Soft Matter

Volume

13

Pub Type

Journals

Download Paper

https://doi.org/10.1039/C7SM00950J

Keywords

additive manufacturing, material extrusion, fused deposition modeling, thermography, fracture mechanics, melt rheology, polymer physics, polymer-polymer welding

Citation

Seppala, J. , Hoon, S. , Hillgartner, K. , Davis, C. and Migler, K. (2017), Weld formation during material extrusion additive manufacturing, Soft Matter, [online], https://doi.org/10.1039/C7SM00950J (Accessed November 21, 2024)