Effect of geometry on the mechanical response of additively manufactured polymer

Joon Phil Choi,Seung Ki Moon,Yongjie Zhang

doi:10.1016/j.polymertesting.2021.107245

Joon Phil Choi, Seung Ki Moon + Show 1 more

Open Access

https://doi.org/10.1016/j.polymertesting.2021.107245

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Abstract

In recent years, there is an rise in adoption of additive manufactured parts as end use parts. The increase is especially apparent in an aviation industry, where benefits such as shortened supply chain and parts on demand enabled significant cost savings. One of the most established AM methods, Fused Deposition Modelling™ (FDM), is widely adopted in the aviation industry to manufacture the end use parts. However, to ensure that FDM parts are able to meet functional requirements, extensive characterisation are required to be performed to understand the impact of manufacturing process parameters on the part performance. Due to Process-Structure-Property (PSP) linkage, toolpath can have a significant influence on FDM part performance. Existing research has focused extensively on the impact of process parameters on the FDM part performance. However, it is believed that toolpath planning, which is significantly less extensively studied, can have influence on the part performance. To investigate the effect, this research utilises 5 different tensile specimens and 2 different fabrication methods, namely specimens printed to net shape and specimens machined from a printed plate. It is concluded that the net shape specimens are substantially strengthened and stabilised due to presence of toolpath features. Due to the PSP linkage, the features translate into favourable improvement in mechanical performance which strengthened the net shaped specimens by up to 51%. This paper characterises influence of the toolpath on the mechanical properties and discusses how the toolpath features such as travel distance, thermal history and contours, impact FDM parts which can aid in prediction of performance of FDM structures.

Highlights

Additive manufacturing (AM) is a unique manufacturing technique where digital files are converted into physical parts, which enables freedom of design for fabrication
Materials used in Fused Deposition ModellingTM (FDM) process are commonly available engineering plastics, such as Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA)
The impact of toolpath planning on the mechanical response was investigated to improve the prediction of FDM part per formance

Summary

Introduction

Additive manufacturing (AM) is a unique manufacturing technique where digital files are converted into physical parts, which enables freedom of design for fabrication. Among the various AM tech nologies, Fused Filament Fabrication, or commonly known as Fused Deposition ModellingTM (FDM), is classified under material extrusion process under [5], and is one of the widely used and has received much attention. It has found niche applications in many industries, including use in biomedical, soft robotics and space [6,7,8]. The semi-molten material is subsequently deposited on the build platform through deposition nozzles, according to pre-defined tool pathing which follows the geometry of the part cross section. The process repeats for the subsequent layers, until the part is completed

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