Effect of gel time of 3D sand printing binder system on quality of sand mold/core

Wang, Yan; Yu, Ruilong; Tan, Rui; Lou, Yan-chun

doi:10.1007/s41230-021-1085-8

Cited by 4 publications

(2 citation statements)

References 7 publications

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“…[ 5 ] Gravity is negligible because of the low mass of the droplets. [ 36,37 ] The gel time of furan resins is in the order of minutes [ 38 ] and was thus expected not to influence the binder infiltration behavior as it was investigated herein. The simulation time was set to 0.6 s.…”

Section: Numerical Modelingmentioning

confidence: 99%

Simulation of Binder Infiltration in Additive Manufacturing of Sand Molds

Erhard,

Tanjavooru,

Hartmann

et al. 2023

Adv Eng Mater

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This article proposes a CFD approach to simulate binder infiltration in 3D printing of sand molds using OpenFOAM facilitating the identification of suitable levers for application‐specific material and process developments. A method for randomly generating powder bulks of designated powder size distributions (PSD) and procedures for automated analysis of the infiltration profile and volume are introduced. Simulation is utilized to investigate binder infiltration using different droplet spacings, representing different printheads’ resolutions. The apparent particle size at the exact location of the droplets’ impact, the droplets’ landing position in relation to the respective surface topography, and thus the statistical appearance of particle formations appear to be influencing the infiltration profile. High‐speed camera observations show the plausibility of the predicted infiltration kinetics. An exemplary use case compares the predicted infiltration profiles to the compressive strength of specimens printed from silica sand with low binder contents. Simulation predicts an average infiltration of 250 µm that presumably achieves reliable bonding for layer thicknesses up to 365 µm. A decrease in strength with increasing layer thickness at constant binder contents can be found in the experiment – at layer thicknesses above 350 µm, only minor strengths are achieved.This article is protected by copyright. All rights reserved.

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Section: Numerical Modelingmentioning

confidence: 99%

Simulation of Binder Infiltration in Additive Manufacturing of Sand Molds

Erhard,

Tanjavooru,

Hartmann

et al. 2023

Adv Eng Mater

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“…High-modulus molds such as steels are inherently difficult to process; besides, they are heavy in weight. The sacrificial molds like sand molds and wax molds , require the otherwise supportive force for shape retention. Either the precision or the processing of traditional molds must be conquered for the molding of materials with complex structures.…”

Section: Introductionmentioning

confidence: 99%

Reconfigurable, Solvent-Processable, NIR-Triggerable Shape Memory Cyanate Esters for Smart Molds

Tang

Deng

Cao

et al. 2023

ACS Appl. Mater. Interfaces

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Shape memory polymer (SMP)-based smart molds, which could provide high-resolution mold shape and morph in response to external stimuli for readily demolding the complex structure, attract extensive attention. However, the suitable SMP for smart molds is usually confined with low stretchability that likely causes damage during demolding. Herein, we present a cyanate ester smart composite (CESC) with a reconfigurable, solvent-processable, and near-infrared (NIR)-triggerable shape memory effect (SME), which enables the 2D sheet with a variety of morphed complex shapes through deformation in a mild situation. Notably, the reconfigurable SME and the recyclability of the shape memory cyanate ester (SMCE) were addressed for the first time, attributed to the dynamic covalent bonds of transesterification and the novel cyanurate exchange. In addition, we found that the mechanism of solvent-processable SME is attributed to the varied cross-linking density and the mobility of the polymer chain. Integrating the multiple responsive SME and reconfigurable SME, the CESC demonstrated versatile applications as a smart mold. The results demonstrate a wide scope of application of the integrated SME and provide a new design strategy for thermoset cyanate materials.

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