<?xml version="1.0" encoding="utf-8"?>
<export-example>
  <doc>
    <id>41242</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Investigation of solidification cracking susceptibility of type 316L stainless steel during laser beam welding using an in-situ observation technique</title>
    <abstract language="eng">This technique is the first to provide a measurement of the full strain field locally in the immediate vicinity of the solidification front. Automatic identification of the cases that can be critical for the solidification crack formation the described procedure of the optical measurement allows the real material-dependent values of critical strain characterising the transition to hot cracking during laser welding processes to be determined. The local critical strain in vicinity of the solidification front has observed between 3.6 and 4.2%.</abstract>
    <enrichment key="eventName">Lasers in Manufacturing Conference 2017</enrichment>
    <enrichment key="eventPlace">Munich, Germany</enrichment>
    <enrichment key="eventStart">26.06.2017</enrichment>
    <enrichment key="eventEnd">29.06.2017</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Nasim Bakir</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical measurment technique</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solidification cracking</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser beam Welding</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>55644</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>335</pageFirst>
    <pageLast>339</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>111</volume>
    <type>article</type>
    <publisherName>Elsevier B.V.</publisherName>
    <publisherPlace>Amsterdam</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Preliminary study to investigate the applicability of optical strain measurement technique for the detection of hot cracks in laser metal deposited layers</title>
    <abstract language="eng">Laser metal deposition (LMD) as an additive manufacturing technique became increasingly important in recent years and thus the demand for component safety. This is the reason, for the need for reliable in-situ defect detection techniques. For laser beam weld seams an optical measurement technique based on an optical flow algorithm was successfully used to define the critical straining conditions that lead to hot cracking. This algorithm was adapted for bead-on-plate weld seams on LMD deposited layers of IN718 alloy while performing external strain on the specimen in an externally loaded hot cacking test facility. The resulting transversal hot cracks along the weld seam were localized via X-Ray inspection and the type of cracking confirmed by Scanning Electron Microscopy (SEM). The strain distribution was measured in the vicinity of the solidification front and correlated to the detected hot cracks. Based on the results this technique could be adopted for LMD experiments.</abstract>
    <parentTitle language="eng">Procedia CIRP</parentTitle>
    <identifier type="doi">10.1016/j.procir.2022.08.034</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-556445</identifier>
    <enrichment key="eventName">12th CIRP Conference on Photonic Technologies [LANE 2022]</enrichment>
    <enrichment key="eventPlace">Fürth, Germany</enrichment>
    <enrichment key="eventStart">04.09.2022</enrichment>
    <enrichment key="eventEnd">08.09.2022</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Anne Straße</author>
    <author>Nasim Bakir</author>
    <author>Andrey Gumenyuk</author>
    <author>Michael Rethmeier</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser Metal Deposition (LMD)</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Strain measurement</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical flow</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.3 Schweißtechnische Fertigungsverfahren</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/55644/1-s2.0-S2212827122009131-main.pdf</file>
  </doc>
  <doc>
    <id>51307</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>666</pageFirst>
    <pageLast>670</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>94</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">In situ determination of the critical straining condition for solidification cracking during laser beam welding</title>
    <abstract language="eng">A self-restraint hot cracking test (free edge test) was used in combination with a novel optical measurement technique to determine the critical straining conditions for solidification cracking for the stainless steel grade 1.4828 (AISI 309). The Lucas-Kanade algorithm for the optical flow (OF) calculation was implemented to obtain the full-field displacement and then the full-field strain. &#13;
The use of external laser illumination with appropriate filters allows to obtain good image quality with good contrast. The critical straining conditions required for solidification cracking can be obtained by means the proposed technique in the immediate vicinity of the solidification front. A very good repeatability was demonstrated for the used measurement technique. The critical straining conditions for solidification cracking for the tested steel und under this welding conditions has been detected</abstract>
    <parentTitle language="eng">Procedia CIRP</parentTitle>
    <identifier type="doi">10.1016/j.procir.2020.09.104</identifier>
    <identifier type="issn">2212-8271</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-513070</identifier>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <licence>Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International</licence>
    <author>Nasim Bakir</author>
    <author>Andrey Gumenyuk</author>
    <author>V. Pavlov</author>
    <author>S. Volvenko</author>
    <author>Michael Rethmeier</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser beam welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solidification cracking</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain rate</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical flow</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="institutes" number="">9.0 Abteilungsleitung und andere</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/51307/1-s2.0-S2212827120312919-main.pdf</file>
  </doc>
  <doc>
    <id>44910</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>rus</language>
    <pageFirst>749</pageFirst>
    <pageLast>754</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="rus">Development of a measuring technology of strain field in welds</title>
    <abstract language="eng">In the article considered the problem of hot cracks occurrence during laser welding process. The main reason of their appearance is strain. The optical method for measuring full field strain locally near the solidification front during laser welding process is proposed. The proposed method of optical measurement allows to determine the real values of the critical strain for various materials characterizing the occurrence of hot cracks in laser welding process.</abstract>
    <parentTitle language="eng">20th International Conference Digital Signal Processing</parentTitle>
    <identifier type="isbn">978-5-905278-33-4</identifier>
    <enrichment key="eventName">20th international conference "Digital signal processing and applications DSPA-2018"</enrichment>
    <enrichment key="eventPlace">Moskau, Russia</enrichment>
    <enrichment key="eventStart">28.03.2018</enrichment>
    <enrichment key="eventEnd">30.03.2018</enrichment>
    <author>V.A. Pavlov</author>
    <author>S.V. Zavialov</author>
    <author>Nasim Bakir</author>
    <author>Andrey Gumenyuk</author>
    <author>Michael Rethmeier</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solidification cracking</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Strain rate</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical measurement</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>In situ strain</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Graue Literatur</collection>
  </doc>
  <doc>
    <id>41175</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>7</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Investigation of solidification cracking susceptibility of type 316L stainless steel during laser beam welding using an in-situ observation technique</title>
    <abstract language="eng">Laser welding is a widely established manufacturing process in many industry sectors. Solidification cracking as well as the weldability of materials is still since many years a highly contentious issue, particularly regarding the causes of the hot crack formation. Many of studies have been conducted to determine the critical conditions of occurrence of the solidification cracking. In this study a 2D in-situ observation technique in conjunction with laser diodes as the illuminating source has been employed to measure the arising strain field during the laser beam welding process. For the first time the employed technique enabled the in-situ measurement of the transient strain field at the surface of the workpiece directed to the laser beam in the critical range, where the solidification cracking normally occurs. Thus the critical threshold strain values at high temperatures characterizing transition from crack free to crack concomitant welding process could be deduced.</abstract>
    <parentTitle language="eng">Lasers in Manufacturing Conference 2017</parentTitle>
    <enrichment key="eventName">Lasers in Manufacturing Conference 2017</enrichment>
    <enrichment key="eventPlace">Munich, Germany</enrichment>
    <enrichment key="eventStart">26.06.2017</enrichment>
    <enrichment key="eventEnd">29.06.2017</enrichment>
    <author>V. Pavlov</author>
    <author>Andrey Gumenyuk</author>
    <author>S. Volvenko</author>
    <author>Michael Rethmeier</author>
    <author>Nasim Bakir</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser beam Welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical measurement technique</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solidification cracking</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>43992</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>234</pageFirst>
    <pageLast>240</pageLast>
    <pageNumber/>
    <edition/>
    <issue>3</issue>
    <volume>23</volume>
    <type>article</type>
    <publisherName>Taylor and Francis</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Investigation of solidification cracking susceptibility during laser beam welding using an in-situ observation technique</title>
    <abstract language="eng">In recent years, laser beam welding has found wide applications in many industrial fields. Solidification cracks are one of the most frequently encountered welding defects that hinder obtaining a safe weld joint. Decades of research have shown that one of the main causes of such cracks are the strain and the strain rate. Obtaining meaningful measurements of these strains has always been a major challenge for scientists, because of the specific environment of the measurement range and the many obstacles, as well as the high temperature and the plasma plume. In this study, a special experimental setup with a high-speed camera was employed to measure the strain during the welding process. The hot cracking susceptibility was investigated for 1.4301 stainless steel, and the critical strain required for solidification crack formation was locally and globally determined.</abstract>
    <parentTitle language="eng">SCIENCE AND TECHNOLOGY OF WELDING AND JOINING</parentTitle>
    <identifier type="doi">10.1080/13621718.2017.1367550</identifier>
    <identifier type="issn">1362-1718</identifier>
    <identifier type="issn">1743-2936</identifier>
    <enrichment key="date_peer_review">16.02.2018</enrichment>
    <author>Nasim Bakir</author>
    <author>Andrey Gumenyuk</author>
    <author>Michael Rethmeier</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solidification cracking</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical measurement</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>In situ strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Strain rate</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>47761</id>
    <completedYear/>
    <publishedYear>2019</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>435</pageFirst>
    <pageLast>441</pageLast>
    <pageNumber/>
    <edition/>
    <issue>2</issue>
    <volume>63</volume>
    <type>article</type>
    <publisherName>Springer Berlin Heidelberg</publisherName>
    <publisherPlace>Berlin</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Development of a novel optical measurement technique to investigate the hot cracking susceptibility during laser beam welding</title>
    <abstract language="eng">Using a novel optical measurement technique together with the optical flow algorithm, a two-dimensional deformation analysis during welding was conducted. The presented technique is the first to provide a measurement of the full strain field locally in the immediate vicinity of the solidification front.&#13;
&#13;
Additionally, the described procedure of the optical measurement allows the real material-dependent values of critical strain and strain rate characterizing the transition to hot cracking during laser welding processes to be determined. Furthermore, the above-mentioned technique is independet on the welding process, which means, it can be also used for arc welding processes. Dependency between the external strain rate and the critical local strain and strain rate has been observed. That is to say, the critical local strain and strain rate is increased with an increase of the strain rate.Moreover, this technique allows automatic identification of the cases that can be critical for the solidification crack formation by monitoring the state of strain on the crack-sensitive region within the mushy zone.</abstract>
    <parentTitle language="eng">Welding in the World</parentTitle>
    <identifier type="doi">10.1007/s40194-018-0665-8</identifier>
    <identifier type="issn">0043-2288</identifier>
    <enrichment key="date_peer_review">11.04.2019</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Nasim Bakir</author>
    <author>V. Pavlov</author>
    <author>S. Zavjalov</author>
    <author>S. Volvenko</author>
    <author>Andrey Gumenyuk</author>
    <author>Michael Rethmeier</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical measurment technique</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Hot crack</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser beam welding</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
</export-example>
