Effect of temperature on the mechanical properties of 3D-printed PLA tensile specimens

Abstract

Purpose Recent advancements of 3D printing technology have brought forward the interest for this technique in many engineering fields. This study aims to focus on mechanical properties of the polylactic acid (PLA) feeding material under different thermal conditions for a typical fusion deposition of 3D printer system. Design/methodology/approach Specimens were tested under static loading within the range 20ºC to 60ºC considering different infill orientations. The combined effect of temperature and filament orientation is investigated in terms of constitutive material parameters and final failure mechanisms. The difference between feeding system before and post-3D printing was also assessed by mechanical test on feeding filament to verify the thermal profile during the deposition phase. Findings The results in terms of Young’s modulus, ultimate tensile strength (UTS), strain at failure (εf) and stress at failure (σf) are presented and discussed to study the influence of process settings over the final deposited material. Fracture surfaces have been investigated using an optical microscope to link the phenomenological interpretation of the failure with the micro-mechanical behaviour. Experimental results show a strong correlation between stiffness and strength with the infill orientation and the temperature values. Moreover, a relevant effect is related to deformed geometry of the filament approaching glass transition region of the polymer according to the deposition orientation. Research limitations/implications The developed method can be applied to optimise the stiffness and strength of any 3D-printed composite according to the infill orientation. Practical implications To avoid the failure of specimens outside the gauge length, a previously proposed modification to the geometry was adopted. The geometry has a parabolic profile with a curvature of 1,000 mm tangent to the middle part of the specimen. Originality/value Several authors have reported the stiffness and strength of 3D-printed parts under static and ambient temperature for different build parameters. However, there is a lack of literature on the combination of the latter with the temperature effects on the mechanical properties which this paper covers.

Mechanical properties of 3-D printed truss-like lattice biopolymer non-stochastic structures for sandwich panels with natural fibre composite skins

“…Due to its low melting temperature and ease of printing PLA can even be used by consumers to make finished products [19]. The mechanical properties of FFF/FDM PLA are well established [20][21][22][23], and their chemical resistance is also known [24]. PLA has also been successfully used in a number of polymer matrix composites [25][26][27][28][29][30].…”

A method for generating intensity‐modulated radiation therapy fields for small animal irradiators utilizing 3D‐printed compensator molds

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“…Firstly, high temperature of liquified Cerrobend (~70°C) deformed the PLA mold, probably due to decreased Young's Modulus near its glass transition temperature of 60°C rendering the resulting compensator unstable. 22 In addition, Cerrobend formed a prominent meniscus on the PLA mold when poured, which then quickly hardened. Metal-infused PLA filaments offered an alternative to the mold approach, in that the compensator could be directly 3D printed without a mold.…”

Influence of Structural Characteristics on the Mechanical Properties of FDM Printed PLA Material

“…Several research teams [7][8][9][10] have investigated printing by the biodegradable polylactide (PLA) and reported on the resultant mechanical properties. Lanzotti et al [7] reported the effect of process parameters on tensile properties, including a decrease in strength as the infill orientation approaches 90 degrees and an increase as the perimeters increase.…”

“…Lanzotti et al [7] reported the effect of process parameters on tensile properties, including a decrease in strength as the infill orientation approaches 90 degrees and an increase as the perimeters increase. Grasso et al [8] went on to show a strong correlation between stiffness and strength with infill orientation and temperature. They considered the deformed geometry of the filament approaching the glass transition region of the polymer according to the deposition orientation.…”