Ultrasound directed self-assembly of filler in continuous flow of a viscous medium through an extruder nozzle for additive manufacturing

Felt, Alan; Raeymaekers, Bart

doi:10.1016/j.addlet.2023.100120

Cited by 6 publications

(3 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the equation, Q ultrasound represents the equivalent energy of ultrasonic vibration, which is the energy absorbed per unit volume of molten material (J/m 3 ); I represents the acoustic intensity of the ultrasonic waves; and α represents the ultrasonic attenuation coefficient of the substrate, which can be calculated using Equation (13), where N is a number not greater than 10 [11].…”

Section: Ultrasonic Energy Equivalencementioning

confidence: 99%

The Research on Ultrasonic Vibration Amplitudes in Ti6Al4V DED Additive Manufacturing

Liu,

Zhang,

et al. 2023

Alloys

View full text Add to dashboard Cite

Ultrasonic-assisted Ti6Al4V Directed Energy Deposition (DED) additive manufacturing technology can improve the problem of uneven microstructure caused by laser heating and sudden cooling of the molten pool. In this paper, the numerical analysis and experimental verification methods were adopted. The influencing factors, such as the cavitations’ effect, sound flow enhancement effect, and sound flow thermal effect related to the ultrasonic assistance in the molten pool, were analyzed. After equating the energy of the ultrasound, the model of additive manufacturing was introduced in the form of a heat source. The temperature gradient changes during the solidification process of the molten pool with the addition of ultrasound assistance and the effect of ultrasonic vibration during the manufacturing process on its deposited state and microstructure of solution-aged formed parts were studied. The results showed that when the wire feeding rate is 5 mm/s and the laser scanning speed is 5 mm/s, the optimal laser power is 1000 W~1100 W, corresponding to the optimal ultrasonic amplitude of 120 μm. Then, by comparing the temperature field with the same amplitude of 0 μm (i.e., no ultrasonic vibration) and the microstructure of the formed parts, it was verified that ultrasonic vibration facilitates fluid flow in the molten pool, which could lead to a more uniform temperature distribution. This optimized approach not only enhances the understanding of the process but also contributes significantly to the advancement of related research endeavors.

show abstract

Section: Ultrasonic Energy Equivalencementioning

confidence: 99%

The Research on Ultrasonic Vibration Amplitudes in Ti6Al4V DED Additive Manufacturing

Liu,

Zhang,

et al. 2023

Alloys

View full text Add to dashboard Cite

show abstract

“…However, it is well known that the viscosity of a mixture of polymer and filler increases with increasing filler fraction, [22][23][24] which may cause the FFF or DIW extruder nozzle to clog. [25,26] Several researchers have also emphasized the importance of photopolymer viscosity during VP. Low-viscosity photopolymer is generally desirable because it ensures that the surface of each new layer self-levels or, alternatively, levels by means of wiperblade recoating.…”

Section: Introductionmentioning

confidence: 99%

Viscosity of Mono‐ and Polydisperse Mixtures of Photopolymer and Rigid Spheres for Manufacturing of Engineered Composite Materials Using Vat Photopolymerization

Reynolds,

Unterhalter,

Francoeur

et al. 2024

Adv Eng Mater

Self Cite

View full text Add to dashboard Cite

Vat photopolymerization (VP) additive manufacturing involves selectively curing low‐viscosity photopolymers via exposure to ultraviolet light in a layer‐wise fashion. Dispersing filler materials in the photopolymer enables tailored end‐use properties, but also drastically increases the viscosity and the timescale associated with interparticle network structural recovery post‐shear. These rheological properties strongly influence self‐leveling and recoating of the liquid photopolymer mixture during VP. Here, we experimentally determine viscosity of photopolymer and rigid spherical glass microparticles (filler) as a function of filler fraction, filler size distribution (mono‐ and polydisperse), shear rate, and temperature, which are important VP process parameters. Employing existing viscosity models for mono‐ and polydisperse polymer mixtures demonstrates that particle‐particle interactions and the formation of non‐spherical clusters of particles strongly affect the viscosity of both monodisperse and polydisperse mixtures with particle volume fractions > 0.05 due to agglomeration/de‐agglomeration of clusters at elevated shear rates. Consequently, unmodified viscosity models, which assume uniformly dispersed, rigid, spherical particles, are applicable only for mixtures with particle volume fractions < 0.05. We show that modifying model parameters such as the fluidity limit and intrinsic viscosity, which explicitly account for non‐spherical clusters of particles, improves agreement between viscosity models and experiments, in particular when using a fractal approach.This article is protected by copyright. All rights reserved.

show abstract

“…Dispersing filler material in the photopolymer resin to modify the properties of the 3D printed specimen changes its curing characteristics. The filler scatters light, which affects the penetration depth of the light into the photopolymer resin, and it also increases the viscosity of the photopolymer, which modifies the polymerization reaction. − However, the ability to increase the filler fraction dispersed in the photopolymer resin is important to 3D print material specimens for specific engineering applications, such as structural polymer matrix composite materials where the filler provides strength and stiffness, − dental composite materials where the filler provides wear resistance, electrical and thermal conductive polymer matrix composite materials where the filler creates a percolated network, ,− or polymer matrix composite materials with ceramic filler that, following resin pyrolysis particle sintering, finds use in biological and high-temperature environments. − Consequently, it is crucial to understand the curing characteristics of the photopolymer resin as a function of the filler fraction.…”

Section: Introductionmentioning

confidence: 99%

Curing Characteristics of a Photopolymer Resin with Dispersed Glass Microspheres in Vat Polymerization 3D Printing

Liang,

Francoeur,

Williams

et al. 2023

ACS Appl. Polym. Mater.

Self Cite

View full text Add to dashboard Cite

The curing characteristics of a photopolymer resin determine the relationship between the vat polymerization (VP) process parameters and the layer thickness, geometric accuracy, and surface roughness of the three-dimensional (3D) printed specimens. Dispersing a filler material into the photopolymer resin to modify the properties of the specimens changes the curing characteristics because the filler scatters, absorbs, and transmits light, which alters the photopolymerization reaction. However, the ability to cure the photopolymer resin with a high filler volume fraction is important to 3D print specimens for specific applications, such as composite and ceramic materials for biological and high-temperature environments. We specifically consider a translucent filler and methodically measure the curing characteristics of a diacrylate/epoxy photopolymer resin with dispersed translucent glass microspheres. Experiments relate the curing depth, degree-of-cure, geometric accuracy, and surface roughness to the exposure dose, filler fraction, and filler size distribution. The curing depth depends on two competing effects: light scattering and light transmission through the translucent filler, and it increases with increasing filler fraction for low exposure dose, which contrasts results documented by others for VP with an opaque filler. Furthermore, the degree-of-cure increases with increasing filler fraction for a constant exposure dose. The geometric accuracy and surface roughness of the 3D printed specimens decrease with increasing exposure dose and filler fraction. This work has implications for VP of photopolymer resins with high filler fraction in the context of manufacturing of engineered materials.

show abstract

Ultrasound directed self-assembly of filler in continuous flow of a viscous medium through an extruder nozzle for additive manufacturing

Cited by 6 publications

References 41 publications

The Research on Ultrasonic Vibration Amplitudes in Ti6Al4V DED Additive Manufacturing

The Research on Ultrasonic Vibration Amplitudes in Ti6Al4V DED Additive Manufacturing

Viscosity of Mono‐ and Polydisperse Mixtures of Photopolymer and Rigid Spheres for Manufacturing of Engineered Composite Materials Using Vat Photopolymerization

Curing Characteristics of a Photopolymer Resin with Dispersed Glass Microspheres in Vat Polymerization 3D Printing

Contact Info

Product

Resources

About