No Cover Image

Journal article 349 views 98 downloads

Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture

Amal Charles, Ahmed Elkaseer, Umberto Paggi, Lore Thijs, Veit Hagenmeyer, Steffen Scholz

Additive Manufacturing, Volume: 46, Start page: 102148

Swansea University Author: Steffen Scholz

  • 57252.pdf

    PDF | Version of Record

    © 2021 The Authors. This is an open access article under the CC BY license

    Download (25.83MB)

Check full text

DOI (Published version): 10.1016/j.addma.2021.102148

Abstract

Down-facing surfaces are one of the most challenging features in metal parts produced by laser powder bed fusion (LPBF). A combination of reasons, primary of which are residual stresses and overheating cause these features to have the worst surface finish and dimensional accuracy of all LPBF surface...

Full description

Published in: Additive Manufacturing
ISSN: 2214-8604
Published: Elsevier BV 2021
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa57252
Tags: Add Tag
No Tags, Be the first to tag this record!
first_indexed 2021-07-01T08:40:27Z
last_indexed 2021-08-05T03:16:54Z
id cronfa57252
recordtype SURis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2021-08-04T15:08:33.3117075</datestamp><bib-version>v2</bib-version><id>57252</id><entry>2021-07-01</entry><title>Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture</title><swanseaauthors><author><sid>20c4a48c9bf558852c28f1640e01ef50</sid><firstname>Steffen</firstname><surname>Scholz</surname><name>Steffen Scholz</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2021-07-01</date><deptcode>FGSEN</deptcode><abstract>Down-facing surfaces are one of the most challenging features in metal parts produced by laser powder bed fusion (LPBF). A combination of reasons, primary of which are residual stresses and overheating cause these features to have the worst surface finish and dimensional accuracy of all LPBF surfaces. In order to examine this phenomenon, a Design of Experiments (DoE) study is conducted for three different inclination angles, namely 45&#xB0;, 35&#xB0; and 25&#xB0; and for two different layer thicknesses of 60 &#xB5;m and 90 &#xB5;m. The results from the DoE are used to establish quadratic regression equations that can be used to predict the quality marks of surface roughness and the relative dimensional error.This fundamental investigation helps to explain the reasons for the major defects in down-facing surfaces of parts produced with Ti-6AL-4V material, namely the dross formation and attempts to improve the predictability of quality within the region. Further to the establishment of the quadratic equations, a discussion is conducted on the thermomechanical processes involved in the mechanism of dross formation and explanations are given on the reasons behind the observed physical phenomena. The trend of the propagation of (Root Mean Square) RMS Surface roughness (Sq) and the relative dimensional error with respect to the Volumetric Energy Density (VED) is discussed in detail. The respective quadratic equations are then tested by a second round of validation prints, and the results confirm the feasibility of the developed quadratic models to accurately predict process outcomes especially when operating near the suggested optimal printing zones. The high roughness of low VED printing is attributed to the formation of &#x2018;inverse mushroom&#x2019; structures, and the low roughness of high VED surface is attributed to the formation of large flat regions formed as adjacent meltpools that can fuse together at various locations.</abstract><type>Journal Article</type><journal>Additive Manufacturing</journal><volume>46</volume><journalNumber/><paginationStart>102148</paginationStart><paginationEnd/><publisher>Elsevier BV</publisher><placeOfPublication/><isbnPrint/><isbnElectronic/><issnPrint>2214-8604</issnPrint><issnElectronic/><keywords>Laser Powder Bed Fusion, Ti6Al4V, Down-facing surfaces, Dross formation, As-built quality</keywords><publishedDay>1</publishedDay><publishedMonth>10</publishedMonth><publishedYear>2021</publishedYear><publishedDate>2021-10-01</publishedDate><doi>10.1016/j.addma.2021.102148</doi><url/><notes/><college>COLLEGE NANME</college><department>Science and Engineering - Faculty</department><CollegeCode>COLLEGE CODE</CollegeCode><DepartmentCode>FGSEN</DepartmentCode><institution>Swansea University</institution><apcterm/><lastEdited>2021-08-04T15:08:33.3117075</lastEdited><Created>2021-07-01T09:38:10.7743461</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Uncategorised</level></path><authors><author><firstname>Amal</firstname><surname>Charles</surname><order>1</order></author><author><firstname>Ahmed</firstname><surname>Elkaseer</surname><order>2</order></author><author><firstname>Umberto</firstname><surname>Paggi</surname><order>3</order></author><author><firstname>Lore</firstname><surname>Thijs</surname><order>4</order></author><author><firstname>Veit</firstname><surname>Hagenmeyer</surname><order>5</order></author><author><firstname>Steffen</firstname><surname>Scholz</surname><order>6</order></author></authors><documents><document><filename>57252__20540__857cfdac5bb0494599de477a29067b9a.pdf</filename><originalFilename>57252.pdf</originalFilename><uploaded>2021-08-04T15:07:02.8915364</uploaded><type>Output</type><contentLength>27087649</contentLength><contentType>application/pdf</contentType><version>Version of Record</version><cronfaStatus>true</cronfaStatus><documentNotes>&#xA9; 2021 The Authors. This is an open access article under the CC BY license</documentNotes><copyrightCorrect>true</copyrightCorrect><language>eng</language><licence>http://creativecommons.org/licenses/by/4.0/</licence></document></documents><OutputDurs/></rfc1807>
spelling 2021-08-04T15:08:33.3117075 v2 57252 2021-07-01 Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture 20c4a48c9bf558852c28f1640e01ef50 Steffen Scholz Steffen Scholz true false 2021-07-01 FGSEN Down-facing surfaces are one of the most challenging features in metal parts produced by laser powder bed fusion (LPBF). A combination of reasons, primary of which are residual stresses and overheating cause these features to have the worst surface finish and dimensional accuracy of all LPBF surfaces. In order to examine this phenomenon, a Design of Experiments (DoE) study is conducted for three different inclination angles, namely 45°, 35° and 25° and for two different layer thicknesses of 60 µm and 90 µm. The results from the DoE are used to establish quadratic regression equations that can be used to predict the quality marks of surface roughness and the relative dimensional error.This fundamental investigation helps to explain the reasons for the major defects in down-facing surfaces of parts produced with Ti-6AL-4V material, namely the dross formation and attempts to improve the predictability of quality within the region. Further to the establishment of the quadratic equations, a discussion is conducted on the thermomechanical processes involved in the mechanism of dross formation and explanations are given on the reasons behind the observed physical phenomena. The trend of the propagation of (Root Mean Square) RMS Surface roughness (Sq) and the relative dimensional error with respect to the Volumetric Energy Density (VED) is discussed in detail. The respective quadratic equations are then tested by a second round of validation prints, and the results confirm the feasibility of the developed quadratic models to accurately predict process outcomes especially when operating near the suggested optimal printing zones. The high roughness of low VED printing is attributed to the formation of ‘inverse mushroom’ structures, and the low roughness of high VED surface is attributed to the formation of large flat regions formed as adjacent meltpools that can fuse together at various locations. Journal Article Additive Manufacturing 46 102148 Elsevier BV 2214-8604 Laser Powder Bed Fusion, Ti6Al4V, Down-facing surfaces, Dross formation, As-built quality 1 10 2021 2021-10-01 10.1016/j.addma.2021.102148 COLLEGE NANME Science and Engineering - Faculty COLLEGE CODE FGSEN Swansea University 2021-08-04T15:08:33.3117075 2021-07-01T09:38:10.7743461 Faculty of Science and Engineering School of Engineering and Applied Sciences - Uncategorised Amal Charles 1 Ahmed Elkaseer 2 Umberto Paggi 3 Lore Thijs 4 Veit Hagenmeyer 5 Steffen Scholz 6 57252__20540__857cfdac5bb0494599de477a29067b9a.pdf 57252.pdf 2021-08-04T15:07:02.8915364 Output 27087649 application/pdf Version of Record true © 2021 The Authors. This is an open access article under the CC BY license true eng http://creativecommons.org/licenses/by/4.0/
title Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture
spellingShingle Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture
Steffen Scholz
title_short Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture
title_full Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture
title_fullStr Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture
title_full_unstemmed Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture
title_sort Down-facing surfaces in laser powder bed fusion of Ti6Al4V: Effect of dross formation on dimensional accuracy and surface texture
author_id_str_mv 20c4a48c9bf558852c28f1640e01ef50
author_id_fullname_str_mv 20c4a48c9bf558852c28f1640e01ef50_***_Steffen Scholz
author Steffen Scholz
author2 Amal Charles
Ahmed Elkaseer
Umberto Paggi
Lore Thijs
Veit Hagenmeyer
Steffen Scholz
format Journal article
container_title Additive Manufacturing
container_volume 46
container_start_page 102148
publishDate 2021
institution Swansea University
issn 2214-8604
doi_str_mv 10.1016/j.addma.2021.102148
publisher Elsevier BV
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Uncategorised{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Uncategorised
document_store_str 1
active_str 0
description Down-facing surfaces are one of the most challenging features in metal parts produced by laser powder bed fusion (LPBF). A combination of reasons, primary of which are residual stresses and overheating cause these features to have the worst surface finish and dimensional accuracy of all LPBF surfaces. In order to examine this phenomenon, a Design of Experiments (DoE) study is conducted for three different inclination angles, namely 45°, 35° and 25° and for two different layer thicknesses of 60 µm and 90 µm. The results from the DoE are used to establish quadratic regression equations that can be used to predict the quality marks of surface roughness and the relative dimensional error.This fundamental investigation helps to explain the reasons for the major defects in down-facing surfaces of parts produced with Ti-6AL-4V material, namely the dross formation and attempts to improve the predictability of quality within the region. Further to the establishment of the quadratic equations, a discussion is conducted on the thermomechanical processes involved in the mechanism of dross formation and explanations are given on the reasons behind the observed physical phenomena. The trend of the propagation of (Root Mean Square) RMS Surface roughness (Sq) and the relative dimensional error with respect to the Volumetric Energy Density (VED) is discussed in detail. The respective quadratic equations are then tested by a second round of validation prints, and the results confirm the feasibility of the developed quadratic models to accurately predict process outcomes especially when operating near the suggested optimal printing zones. The high roughness of low VED printing is attributed to the formation of ‘inverse mushroom’ structures, and the low roughness of high VED surface is attributed to the formation of large flat regions formed as adjacent meltpools that can fuse together at various locations.
published_date 2021-10-01T04:12:51Z
_version_ 1763753875005767680
score 11.016235

Similar Items