{"title":"Controlling anisotropy and brittle-to-ductile transitions by varying extrusion width in short fibre reinforced additive manufacturing","authors":"Jiongyi Yan, Emrah Demirci, Andrew Gleadall","doi":"10.1108/rpj-09-2022-0315","DOIUrl":null,"url":null,"abstract":"Purpose Extrusion width, the width of printed filaments, affects multiple critical aspects in mechanical properties in material extrusion additive manufacturing: filament geometry, interlayer load-bearing bonded area and fibre orientation for fibre-reinforced composites. However, this study aims to understand the effects of extrusion width on 3D printed composites, which has never been studied systematically. Design/methodology/approach Four polymers with and without short-fibre reinforcement were 3D printed into single-filament-wide specimens. Tensile properties, mechanical anisotropy and fracture mechanisms were evaluated along the direction of extruded filaments (F) and normal to the interlayer bond (Z). Extrusion width, nozzle temperature and layer height were studied separately via single-variable control. The extrusion width was controlled by adjusting polymer flow in the manufacturing procedure (gcode), where optimisation can be achieved with software/structure design as opposed to hardware. Findings Increasing extrusion width caused a transition from brittle to ductile fracture, and greatly reduced directional anisotropy for strength and ductility. For all short fibre composites, increasing width led to an increase in strain-at-break and decreased strength and stiffness in the F direction. In the Z direction, increasing width led to increased strength and strain-at-break, and stiffness decreased for less ductile materials but increased for more ductile materials. Originality/value The transformable fracture reveals the important role of extrusion width in processing-structure-property correlation. This study reveals a new direction for future research and industrial practice in controlling anisotropy in additive manufacturing. Increasing extrusion width may be the simplest way to reduce anisotropy while improving printing time and quality in additive manufacturing.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":"74 1","pages":"0"},"PeriodicalIF":3.4000,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Rapid Prototyping Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1108/rpj-09-2022-0315","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose Extrusion width, the width of printed filaments, affects multiple critical aspects in mechanical properties in material extrusion additive manufacturing: filament geometry, interlayer load-bearing bonded area and fibre orientation for fibre-reinforced composites. However, this study aims to understand the effects of extrusion width on 3D printed composites, which has never been studied systematically. Design/methodology/approach Four polymers with and without short-fibre reinforcement were 3D printed into single-filament-wide specimens. Tensile properties, mechanical anisotropy and fracture mechanisms were evaluated along the direction of extruded filaments (F) and normal to the interlayer bond (Z). Extrusion width, nozzle temperature and layer height were studied separately via single-variable control. The extrusion width was controlled by adjusting polymer flow in the manufacturing procedure (gcode), where optimisation can be achieved with software/structure design as opposed to hardware. Findings Increasing extrusion width caused a transition from brittle to ductile fracture, and greatly reduced directional anisotropy for strength and ductility. For all short fibre composites, increasing width led to an increase in strain-at-break and decreased strength and stiffness in the F direction. In the Z direction, increasing width led to increased strength and strain-at-break, and stiffness decreased for less ductile materials but increased for more ductile materials. Originality/value The transformable fracture reveals the important role of extrusion width in processing-structure-property correlation. This study reveals a new direction for future research and industrial practice in controlling anisotropy in additive manufacturing. Increasing extrusion width may be the simplest way to reduce anisotropy while improving printing time and quality in additive manufacturing.
期刊介绍:
Rapid Prototyping Journal concentrates on development in a manufacturing environment but covers applications in other areas, such as medicine and construction. All papers published in this field are scattered over a wide range of international publications, none of which actually specializes in this particular discipline, this journal is a vital resource for anyone involved in additive manufacturing. It draws together important refereed papers on all aspects of AM from distinguished sources all over the world, to give a truly international perspective on this dynamic and exciting area.
-Benchmarking – certification and qualification in AM-
Mass customisation in AM-
Design for AM-
Materials aspects-
Reviews of processes/applications-
CAD and other software aspects-
Enhancement of existing processes-
Integration with design process-
Management implications-
New AM processes-
Novel applications of AM parts-
AM for tooling-
Medical applications-
Reverse engineering in relation to AM-
Additive & Subtractive hybrid manufacturing-
Industrialisation