Selective laser sintering of polymer nanocomposites

Wahab, Md Saidin (2008) Selective laser sintering of polymer nanocomposites. PhD thesis, The University of Leeds.

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Abstract

This thesis presents research to investigate the use of polymer nanocomposites (PNCs) as a raw material for the selective laser sintering (SLS) process. The novelty of this work lies in the fact that PNC materials have been prepared for the SLS process through mechanica1 blending (ball milling) and solution blending technique;. PNC materials containing a polyamide (PA) and nano particles (5wt%) were produced by mechanical blending and solution blending with the aim to improve the mechanical properties. In mechanical blending, commercial Durafom PA was tumble and balI milled with several nano particle materials: yttrium stabilised zirconia (Y SZ), Benton 166 (B166), Bentolite WH (BWH) and Mineral colloide MO (MCMO). For solution blending, commercial: polyamide 6 (PA6) was dissolved in formic acid (HC02H) together with the same nano additive materials used in the mechanical blending and spray-dried to create powder. Material characteristics (physical and chemical elements), thermal properties, powder bed density and flowability of the materials have all been investigated. The materials were processed on a COz SLS experimental machine where the SLS processing characteristics and processing parameters were established. Mechanical properties of the PNCs were evaluated and the results were compared with the unfilled base polymer. From the result of the mechanical blending process, only blended DurafordYSZ was successfblly processed by SLS, and results were also limited for the blended DuraformNSZ as a result of improper dispersion of nano particles in the matrix. Good dispersion of additives was achieved by solution blending, however the PA6 was degraded during the material preparation and spray drying process which resulted in the formation of porous structure and low strength. However the addition of 5 wt % nano particles in the PA6 was shown to increase strength by an average of 50-60%. Further work on powder preparation is required in order to fully realise these performance benefits.

Item Type:Thesis (PhD)
Subjects:T Technology > TA Engineering (General). Civil engineering (General) > TA401-492 Materials of engineering and construction. Mechanics of materials
ID Code:1693
Deposited By:Normajihan Abd. Rahman
Deposited On:28 Sep 2011 12:41
Last Modified:28 Sep 2011 12:41

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