Visco-elastic sintering kinetics in virgin and aged polymer powders

J.E. Alvarez*, H. Snijder, T. Vaneker, H. Cheng, A.R. Thornton, S. Luding, T. Weinhart

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

22 Downloads (Pure)

Abstract

This work provides a novel discrete element method (DEM) framework for modelling the visco-elastic sintering kinetics in virgin and aged polymer powders. The coalescence of particle pairs, over long times, is described by a combined three-stage model of the sintering process, where each stage is dominated by a different driving force: adhesive contact force, adhesive inter-surface force and surface tension. The proposed framework is implemented in MercuryDPM, an open-source package for discrete particle simulations. To quantitatively calibrate the particle-scale parameters, Bayesian filtering is used. Experimental data on Polystyrene (PS), Polyamide 12 (PA12), and PEEK powders, both virgin and aged, are analysed and confirm over a wide range of times the existence of the three distinct sintering mechanisms. In good agreement with the experimental observations, the estimation of sintering time is achieved with a significant accuracy compared to Frenkel's model. This study provides an efficient and reliable approach for future studies of strength evolution in powder-bed fusion processes.

Original languageEnglish
Article number117000
JournalPowder technology
Volume397
Early online date24 Nov 2021
DOIs
Publication statusPublished - Jan 2022

Keywords

  • Bayesian calibration
  • Discrete element method
  • Polymer powders
  • Sintering
  • Visco-elastic kinetics
  • UT-Hybrid-D

Fingerprint

Dive into the research topics of 'Visco-elastic sintering kinetics in virgin and aged polymer powders'. Together they form a unique fingerprint.

Cite this