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Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes / Robert J. Sampson

Swansea University Author: Robert J. Sampson

DOI (Published version): 10.23889/Suthesis.52474

Abstract

Additive Manufacturing (AM) processes have previously benefited from the introduction of parameter monitoring systems, with melt pool monitoring majorly contributing to this field of research. Current melt pool monitoring systems are typically emissivity-based image processing techniques. Melt pool mo...

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Published: Swansea 2019
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
URI: https://cronfa.swan.ac.uk/Record/cronfa52474
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first_indexed 2019-10-16T14:26:47Z
last_indexed 2023-01-11T14:29:38Z
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fullrecord <?xml version="1.0"?><rfc1807><datestamp>2022-12-18T09:54:22.9391941</datestamp><bib-version>v2</bib-version><id>52474</id><entry>2019-10-16</entry><title>Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes</title><swanseaauthors><author><sid>d36079693207431fd9b34ee27a8edce7</sid><ORCID>NULL</ORCID><firstname>Robert J.</firstname><surname>Sampson</surname><name>Robert J. Sampson</name><active>true</active><ethesisStudent>true</ethesisStudent></author></swanseaauthors><date>2019-10-16</date><abstract>Additive Manufacturing (AM) processes have previously bene&#xFB01;ted from the introduction of parameter monitoring systems, with melt pool monitoring majorly contributing to this &#xFB01;eld of research. Current melt pool monitoring systems are typically emissivity-based image processing techniques. Melt pool monitoring systems have successfully been used to grant advanced process understanding, develop control systems and improve deposition quality. By improving the optical acquisition techniques in melt pool monitoring systems, a more enhanced and clearer image of the melt pool has been created, which contains features that indicate the true edges. These new features have been used to compare the conventional emissivity-based image processing techniques with a newly developed image process-ing technique. Comparing both techniques with extracted frames has highlighted potential &#xFB02;aws in conventional image processing algorithms and improved the understanding of melt pool radiation me-chanics and dynamics throughout direct energy deposition processes. The newly developed algorithm provided more accurate melt pool width calculations when compared with the emissivity-based edge detection technique and has been used to study changes in melt pool width with varying laser power settings. The new algorithm was used for subsequent parametric studies to understand the relationship between powder mass &#xFB02;ow rate, path velocity and melt pool width. It was discovered that the rela-tionship between these parameters and melt pool width was complex and further parametric studies using the optimised melt pool algorithm should be conducted. The new algorithm was successfully used to calculate melt pool widths for multiple materials without the need for emissivity values. Melt pool width calculations were performed on multiple materials after minor calibration procedures.</abstract><type>E-Thesis</type><journal/><volume/><journalNumber/><paginationStart/><paginationEnd/><publisher/><placeOfPublication>Swansea</placeOfPublication><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic/><keywords>Additive Manufacturing, Direct energy deposition, Melt pool monitoring, Near-infrared imaging, Melt pool, process monitoring</keywords><publishedDay>31</publishedDay><publishedMonth>12</publishedMonth><publishedYear>2019</publishedYear><publishedDate>2019-12-31</publishedDate><doi>10.23889/Suthesis.52474</doi><url/><notes>A selection of third party content is redacted or is partially redacted from this thesis.</notes><college>COLLEGE NANME</college><department>College of Engineering</department><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><degreelevel>Doctoral</degreelevel><degreename>Ph.D</degreename><apcterm/><funders/><projectreference/><lastEdited>2022-12-18T09:54:22.9391941</lastEdited><Created>2019-10-16T12:19:42.4454915</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>Robert J.</firstname><surname>Sampson</surname><orcid>NULL</orcid><order>1</order></author></authors><documents><document><filename>0052474-16102019125455.pdf</filename><originalFilename>Sampson_Robert_J_PhD_Thesis_Final_Redacted.pdf</originalFilename><uploaded>2019-10-16T12:54:55.9270000</uploaded><type>Output</type><contentLength>72821332</contentLength><contentType>application/pdf</contentType><version>Redacted version - open access</version><cronfaStatus>true</cronfaStatus><embargoDate>2019-10-15T00:00:00.0000000</embargoDate><copyrightCorrect>true</copyrightCorrect></document></documents><OutputDurs/></rfc1807>
spelling 2022-12-18T09:54:22.9391941 v2 52474 2019-10-16 Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes d36079693207431fd9b34ee27a8edce7 NULL Robert J. Sampson Robert J. Sampson true true 2019-10-16 Additive Manufacturing (AM) processes have previously benefited from the introduction of parameter monitoring systems, with melt pool monitoring majorly contributing to this field of research. Current melt pool monitoring systems are typically emissivity-based image processing techniques. Melt pool monitoring systems have successfully been used to grant advanced process understanding, develop control systems and improve deposition quality. By improving the optical acquisition techniques in melt pool monitoring systems, a more enhanced and clearer image of the melt pool has been created, which contains features that indicate the true edges. These new features have been used to compare the conventional emissivity-based image processing techniques with a newly developed image process-ing technique. Comparing both techniques with extracted frames has highlighted potential flaws in conventional image processing algorithms and improved the understanding of melt pool radiation me-chanics and dynamics throughout direct energy deposition processes. The newly developed algorithm provided more accurate melt pool width calculations when compared with the emissivity-based edge detection technique and has been used to study changes in melt pool width with varying laser power settings. The new algorithm was used for subsequent parametric studies to understand the relationship between powder mass flow rate, path velocity and melt pool width. It was discovered that the rela-tionship between these parameters and melt pool width was complex and further parametric studies using the optimised melt pool algorithm should be conducted. The new algorithm was successfully used to calculate melt pool widths for multiple materials without the need for emissivity values. Melt pool width calculations were performed on multiple materials after minor calibration procedures. E-Thesis Swansea Additive Manufacturing, Direct energy deposition, Melt pool monitoring, Near-infrared imaging, Melt pool, process monitoring 31 12 2019 2019-12-31 10.23889/Suthesis.52474 A selection of third party content is redacted or is partially redacted from this thesis. COLLEGE NANME College of Engineering COLLEGE CODE Swansea University Doctoral Ph.D 2022-12-18T09:54:22.9391941 2019-10-16T12:19:42.4454915 Faculty of Science and Engineering School of Engineering and Applied Sciences - Uncategorised Robert J. Sampson NULL 1 0052474-16102019125455.pdf Sampson_Robert_J_PhD_Thesis_Final_Redacted.pdf 2019-10-16T12:54:55.9270000 Output 72821332 application/pdf Redacted version - open access true 2019-10-15T00:00:00.0000000 true
title Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes
spellingShingle Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes
Robert J. Sampson
title_short Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes
title_full Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes
title_fullStr Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes
title_full_unstemmed Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes
title_sort Improved Melt Pool Monitoring Systems for Direct energy Deposition Processes
author_id_str_mv d36079693207431fd9b34ee27a8edce7
author_id_fullname_str_mv d36079693207431fd9b34ee27a8edce7_***_Robert J. Sampson
author Robert J. Sampson
author2 Robert J. Sampson
format E-Thesis
publishDate 2019
institution Swansea University
doi_str_mv 10.23889/Suthesis.52474
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 Additive Manufacturing (AM) processes have previously benefited from the introduction of parameter monitoring systems, with melt pool monitoring majorly contributing to this field of research. Current melt pool monitoring systems are typically emissivity-based image processing techniques. Melt pool monitoring systems have successfully been used to grant advanced process understanding, develop control systems and improve deposition quality. By improving the optical acquisition techniques in melt pool monitoring systems, a more enhanced and clearer image of the melt pool has been created, which contains features that indicate the true edges. These new features have been used to compare the conventional emissivity-based image processing techniques with a newly developed image process-ing technique. Comparing both techniques with extracted frames has highlighted potential flaws in conventional image processing algorithms and improved the understanding of melt pool radiation me-chanics and dynamics throughout direct energy deposition processes. The newly developed algorithm provided more accurate melt pool width calculations when compared with the emissivity-based edge detection technique and has been used to study changes in melt pool width with varying laser power settings. The new algorithm was used for subsequent parametric studies to understand the relationship between powder mass flow rate, path velocity and melt pool width. It was discovered that the rela-tionship between these parameters and melt pool width was complex and further parametric studies using the optimised melt pool algorithm should be conducted. The new algorithm was successfully used to calculate melt pool widths for multiple materials without the need for emissivity values. Melt pool width calculations were performed on multiple materials after minor calibration procedures.
published_date 2019-12-31T04:04:52Z
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score 11.016258

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