Characterization of the effect of in-process annealing using a novel print head assembly on the ultimate tensile strength & toughness of Fused Filament Fabrication (FFF) parts

ABSTRACT

Improving the quality of parts printed using Fused Filament Fabrication (FFF) is of critical importance in a number of engineering applications. Providing additional thermal energy during printing by external means, or by an integrated heater has been investigated in the past to prolong the cooling curve, and therefore, ensure good adhesion with adjacent filaments. This work presents a modified heater block assembly to apply in-process thermal load during the upright printing of a Polylactic Acid (PLA) part. The design overcomes key shortcomings of past work and, in particular, addresses effective printing of thin, tall structures, where filament adhesion between layers is of particular importance. Cross-section imaging and tensile testing is combined with a comprehensive statistical design of experiments in order to fully understand the impact of process parameters on improved mechanical strength of printed parts. This work contributes towards improved properties and performance of realistic and practical FFF-printed parts.

KEYWORDS:

• Fused Filament Fabrication
• in situ heating
• mechanical strength
• statistical analysis

Conflict of interest statement

Robert Taylor has a potential research conflict of interest due to a financial interest with Optimal Structures LLC. A management plan has been created to preserve objectivity in research in accordance with University of Texas at Arlington policy.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Notes on contributors

Parimal Patel

Parimal Patel is pursuing a PhD in Mechanical Engineering at the University of Texas at Arlington. His research interests include additive manufacturing, bio-medical product development, robotics and computer aided design, and heat transfer. He is enthusiastic about teaching and also has 3+ years of experience using additive manufacturing in bio-medical industry.

Rhugdhrivya Rane

Rhugdhrivya Rane holds a PhD degree in Mechanical Engineering from the University of Texas at Arlington where his research focused on improving mechanical properties of fused filament fabricated parts.

Manjarik Mrinal

Manjarik Mrinal holds a PhD degree in Mechanical Engineering from the University of Texas at Arlington where his research focused developing fused filament fabrication technologies to enhance mechanical properties of fused filament fabricated parts. He currently works as a researcher in HP labs.

Vishnu Ganesan

Vishnu Ganesan is a PhD student in the Microscale Thermophysics Laboratory at University of Texas at Arlington. His research interests include heat transfer in Li-ion batteries, additive manufacturing and thermal analysis. He has published work in the past on heat transfer submodeling in Li-ion cells and powder bed modeling for additive manufacturing.

Robert Taylor

Robert Taylor is a Professor of Practice in the Mechanical and Aerospace Engineering department at the University of Texas at Arlington. Dr Taylor has a 12+ years of industry experience in general and military aircraft structural analysis with 6+ years working on F-35 structural development. His research areas are structural technology development, process informed structural design optimization for advanced manufacturing, and design for additive manufacturing.

Ankur Jain

Ankur Jain is an Associate Professor in the Mechanical and Aerospace Engineering Department at the University of Texas, Arlington. His research interests include heat transfer in Li-ion batteries, microscale thermal transport, bioheat transfer, microelectromechanical systems, etc. He has published more than 115 journal papers on these topics. He received the UT Arlington President's Award for Excellence in Teaching Award (2022), UT Arlington College of Engineering Outstanding Early Career Award (2017), NSF CAREER Award (2016) and the ASME EPP Division Young Engineer of the Year Award (2013). His research has been supported by National Science Foundation, Department of Energy, Office of Naval Research, Indo-US Science & Technology Forum and other sources.