Effect of layer thickness on the mechanical properties of laser sintered PA12

Being the trendiest Additive Manufacturing method in industry application as its wide material range availability and complex shape printing ability, Selective Laser Sintering still has extensive range of unidentified properties in the material and process factor employed. The author has conducted s...

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Bibliographic Details
Main Author: Lee, Shin Da
Other Authors: Zhou Kun
Format: Final Year Project (FYP)
Language:English
Published: 2016
Subjects:
Online Access:http://hdl.handle.net/10356/68913
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author Lee, Shin Da
author2 Zhou Kun
author_facet Zhou Kun
Lee, Shin Da
author_sort Lee, Shin Da
collection NTU
description Being the trendiest Additive Manufacturing method in industry application as its wide material range availability and complex shape printing ability, Selective Laser Sintering still has extensive range of unidentified properties in the material and process factor employed. The author has conducted several mechanical testings include tensile testing, impact testing and hardness testing to determine the effect of layer thickness on Polyamide 12 (PA12). Additionally, degree of crystallization of material in various section thicknesses with two categories of layer thickness (100 and 120µm) were obtained by differential scanning calorimetry and to explain the outcome of mechanical testings. The polished surfaces of PA12 with different layer thicknesses were also observed by the author under optical microscope. Results indicated that the thicker layer presents a brittle behavior leads to slight higher tensile properties on the contrary noticeable lower toughness and ductility. The more crystalline region and higher porosity in greater layer thickness are the explanations of more brittle manner. The thinner layer thickness specimens have better sintering efficiency to reduce porosity but during re-crystallization, it processes faster cooling rate that causes lower crystallinity. Insignificant difference of hardness was found between two layer thicknesses. The larger width specimens appeared to have a higher impact strength caused by heat retention during sintering process however hardness and crystallization of material do not vary with section thickness.
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spelling ntu-10356/689132023-03-04T19:15:05Z Effect of layer thickness on the mechanical properties of laser sintered PA12 Lee, Shin Da Zhou Kun School of Mechanical and Aerospace Engineering DRNTU::Engineering Being the trendiest Additive Manufacturing method in industry application as its wide material range availability and complex shape printing ability, Selective Laser Sintering still has extensive range of unidentified properties in the material and process factor employed. The author has conducted several mechanical testings include tensile testing, impact testing and hardness testing to determine the effect of layer thickness on Polyamide 12 (PA12). Additionally, degree of crystallization of material in various section thicknesses with two categories of layer thickness (100 and 120µm) were obtained by differential scanning calorimetry and to explain the outcome of mechanical testings. The polished surfaces of PA12 with different layer thicknesses were also observed by the author under optical microscope. Results indicated that the thicker layer presents a brittle behavior leads to slight higher tensile properties on the contrary noticeable lower toughness and ductility. The more crystalline region and higher porosity in greater layer thickness are the explanations of more brittle manner. The thinner layer thickness specimens have better sintering efficiency to reduce porosity but during re-crystallization, it processes faster cooling rate that causes lower crystallinity. Insignificant difference of hardness was found between two layer thicknesses. The larger width specimens appeared to have a higher impact strength caused by heat retention during sintering process however hardness and crystallization of material do not vary with section thickness. Bachelor of Engineering (Mechanical Engineering) 2016-07-25T01:42:08Z 2016-07-25T01:42:08Z 2016 Final Year Project (FYP) http://hdl.handle.net/10356/68913 en Nanyang Technological University 74 p. application/pdf
spellingShingle DRNTU::Engineering
Lee, Shin Da
Effect of layer thickness on the mechanical properties of laser sintered PA12
title Effect of layer thickness on the mechanical properties of laser sintered PA12
title_full Effect of layer thickness on the mechanical properties of laser sintered PA12
title_fullStr Effect of layer thickness on the mechanical properties of laser sintered PA12
title_full_unstemmed Effect of layer thickness on the mechanical properties of laser sintered PA12
title_short Effect of layer thickness on the mechanical properties of laser sintered PA12
title_sort effect of layer thickness on the mechanical properties of laser sintered pa12
topic DRNTU::Engineering
url http://hdl.handle.net/10356/68913
work_keys_str_mv AT leeshinda effectoflayerthicknessonthemechanicalpropertiesoflasersinteredpa12