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Pore structure evolution during sintering of HDPE particles

Salehi, A ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1016/j.polymer.2019.121865
  3. Publisher: Elsevier Ltd , 2019
  4. Abstract:
  5. Sintering is a processing technique in which loose particles consolidate at elevated temperatures to form porous monoliths. Sintering is also a critical stage in recent additive manufacturing method like selective laser sintering. In this study, using an affordable alternative to X-ray tomography technique, we analyze the pore structure evolution in sintered parts made of nascent high-density polyethylene (HDPE) particles in terms of pore surface genus and pore surface curvature. Also, we investigate the underlying microstructural development and macroscopic properties of sintered parts. It is observed that pore structure and macroscopic permeability are strongly influenced by the development of inter-particle contacts, while mechanical properties are also extensively influenced by microstructural evolution. For instance, the pore evolution is initially limited to surface relaxation and the merging of inter-particle bonds during which macroscopic permeability and relative density remain almost unchanged. However, the rapid mixing of the disentangled polymeric chains of nascent particles through these interfacial regions engenders a distinctive rise in compressive modulus. A study of the pore structure evolution using the approach adopted in this research might also provide the opportunity to understand how various sintering parameters can influence the evolution of inter-particle bonds, which coupled with the microstructural development, control the development of macroscopic properties in sintered porous polymeric parts. © 2019 Elsevier Ltd
  6. Keywords:
  7. Additive manufacturing ; Serial-sectioning ; Structure-property relationship ; 3D printers ; Additives ; High density polyethylenes ; Laser heating ; Mechanical permeability ; Pore structure ; Selective laser sintering ; Structural properties ; High density polyethylene(HDPE) ; Macroscopic permeability ; Macroscopic properties ; Microstructural development ; Processing technique ; Serial sectioning ; Sintering parameters ; Structure property relationships ; Sintering
  8. Source: Polymer ; Volume 183 , 2019 ; 00323861 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0032386119308717