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A study was conducted at the DESY (Deutsches Elektronen\u2010Synchrotron, Hamburg, Germany), in which high-speed synchrotron X ray imaging was used to observe the dynamic shape changes during laser drilling of metals, bridging the gaps left by previous diagnostic techniques. The experimental setup involved an ultrafast YB:YAG laser focused on a sample made from stainless-steel. The X-ray beam enabled the capturing of the formation of a microhole during the drilling process, providing valuable insights into the microhole formation and associated defects. The X-ray image sequences were post-processed using a flat field correction and a Kalman filter to enhance the image quality. In this talk, we delve into the formation of side channels and bulges during the drilling process. In addition, we show the effects of the polarization states of the processing laser on the formation of side channels.", "venue" : "SLT 2024", "eventdate" : "04 - 06 June 2024", "bibtexKey": "Henn.2024.xray.drilling" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2458ade3457d8f95c50d01b418e257285/ifsw", "tags" : [ "myown","ablation","x-ray","ultrashort","nondestructive","drilling","diagnostics","micromaterialprocessing","pulse","stainlesssteel","processmonitoring" ], "intraHash" : "458ade3457d8f95c50d01b418e257285", "interHash" : "9f7482af79f091f70cabbe7164c03207", "label" : "High Speed X-Ray Imaging of Laser Percussion Drilling with Ultrashort Laser Pulses", "user" : "ifsw", "description" : "", "date" : "2025-07-07 19:36:07", "changeDate" : "2025-07-07 19:36:07", "count" : 2, "pub-type": "presentation", "year": "2024", "url": "", "author": [ "Manuel Henn","Lukas Schneller","Matthias Buser","Christian Hagenlocher","Christoph Spurk","Marc Hummel","Felix Beckmann","Julian Moosmann","Thomas Graf" ], "authors": [ {"first" : "Manuel", "last" : "Henn"}, {"first" : "Lukas", "last" : "Schneller"}, {"first" : "Matthias", "last" : "Buser"}, {"first" : "Christian", "last" : "Hagenlocher"}, {"first" : "Christoph", "last" : "Spurk"}, {"first" : "Marc", "last" : "Hummel"}, {"first" : "Felix", "last" : "Beckmann"}, {"first" : "Julian", "last" : "Moosmann"}, {"first" : "Thomas", "last" : "Graf"} ], "abstract": "Percussion drilling of metals with ultrashort pulses has been extensively studied, yet understanding irregularities and defects such as irregular hole shapes, bending, and the formation of side channels remains challenging due to limitations in conventional diagnostics. A study was conducted at the DESY (Deutsches Elektronen\u2010Synchrotron, Hamburg, Germany), in which high-speed synchrotron X ray imaging was used to observe the dynamic shape changes during laser drilling of metals, bridging the gaps left by previous diagnostic techniques. The experimental setup involved an ultrafast YB:YAG laser focused on a sample made from stainless-steel. The X-ray beam enabled the capturing of the formation of a microhole during the drilling process, providing valuable insights into the microhole formation and associated defects. The X-ray image sequences were post-processed using a flat field correction and a Kalman filter to enhance the image quality. In this talk, we delve into the formation of side channels and bulges during the drilling process. In addition, we show the effects of the polarization states of the processing laser on the formation of side channels.", "venue" : "SLT 2024", "eventdate" : "04 - 06 June 2024", "bibtexKey": "Henn.2024.xray.drilling" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2ae9a74f48c02278e8d16fc5a0fd60cf0/manuelhenn", "tags" : [ "ablation","diagnostics","drilling","micromaterialprocessing","myown","nondestructive","processmonitoring","stainlesssteel","ultrashortpulse","x-ray" ], "intraHash" : "ae9a74f48c02278e8d16fc5a0fd60cf0", "interHash" : "56ffbc2b9fc009e155ec5ca0aec781e5", "label" : "The progress of microhole formation during laser percussion drilling of steel observed by highspeed synchrotron x-ray imaging", "user" : "manuelhenn", "description" : "", "date" : "2024-05-14 16:39:48", "changeDate" : "2024-05-14 16:39:48", "count" : 5, "pub-type": "presentation", "year": "2023", "url": "https://wlt.de/sites/default/files/2023-09/Contribution_223.pdf", "author": [ "Manuel Henn","Christian Hagenlocher","Daniel Holder","Daniel J. 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Highspeed synchrotron X-ray imaging was applied to capture the space- and time-resolved evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images show that heat accumulation leads to the formation of a melt film on microhole walls, which dynamically fluctuates during drilling. Additionally, the formation of side channels was observed in the region of the maximum drilling depth where the overall fluence on the microhole walls drops below the threshold fluence. The experimentally captured quantities agree well with existing models and will significantly improve their prediction accuracy.", "eventtitle" : "Lasers in Manufacturing Conference", "venue" : "Munich, Germany", "bibtexKey": "henn2023progress" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2ae9a74f48c02278e8d16fc5a0fd60cf0/ifsw", "tags" : [ "myown","ablation","diagnostics","x-ray","micromaterialprocessing","nondestructive","ultrashortpulse","stainlesssteel","drilling","processmonitoring" ], "intraHash" : "ae9a74f48c02278e8d16fc5a0fd60cf0", "interHash" : "56ffbc2b9fc009e155ec5ca0aec781e5", "label" : "The progress of microhole formation during laser percussion drilling of steel observed by highspeed synchrotron x-ray imaging", "user" : "ifsw", "description" : "", "date" : "2024-05-14 16:39:48", "changeDate" : "2024-05-14 16:39:48", "count" : 5, "pub-type": "presentation", "year": "2023", "url": "https://wlt.de/sites/default/files/2023-09/Contribution_223.pdf", "author": [ "Manuel Henn","Christian Hagenlocher","Daniel Holder","Daniel J. 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Highspeed synchrotron X-ray imaging was applied to capture the space- and time-resolved evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images show that heat accumulation leads to the formation of a melt film on microhole walls, which dynamically fluctuates during drilling. Additionally, the formation of side channels was observed in the region of the maximum drilling depth where the overall fluence on the microhole walls drops below the threshold fluence. The experimentally captured quantities agree well with existing models and will significantly improve their prediction accuracy.", "eventtitle" : "Lasers in Manufacturing Conference", "venue" : "Munich, Germany", "bibtexKey": "henn2023progress" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/27240f95f2b10c0f59ce0e56439d863cd/manuelhenn", "tags" : [ "ablation","diagnostics","drilling","micromaterialprocessing","myown","nondestructive","processmonitoring","pulse","stainlesssteel","ultrashort","x-ray" ], "intraHash" : "7240f95f2b10c0f59ce0e56439d863cd", "interHash" : "bc55142d39b406391173f3bacf6629a2", "label" : "Unveiling laser percussion drilling in metals with ultrashort pulses: insights from high-speed synchrotron x-ray imaging on microhole formation and side channel phenomena", "user" : "manuelhenn", "description" : "", "date" : "2024-05-14 16:29:21", "changeDate" : "2024-05-14 16:29:21", "count" : 5, "pub-type": "presentation", "year": "2024", "url": "https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12873/1287309/Unveiling-laser-percussion-drilling-in-metals-with-ultrashort-pulses/10.1117/12.3003661.full", "author": [ "Manuel Henn","Lukas Schneller","Daniel Holder","Dennis Haasler","Marc Hummel","Felix Beckmann","Julian Moosmann","Christian Hagenlocher","Thomas Graf" ], "authors": [ {"first" : "Manuel", "last" : "Henn"}, {"first" : "Lukas", "last" : "Schneller"}, {"first" : "Daniel", "last" : "Holder"}, {"first" : "Dennis", "last" : "Haasler"}, {"first" : "Marc", "last" : "Hummel"}, {"first" : "Felix", "last" : "Beckmann"}, {"first" : "Julian", "last" : "Moosmann"}, {"first" : "Christian", "last" : "Hagenlocher"}, {"first" : "Thomas", "last" : "Graf"} ], "editor": [ "Rainer Kling","Wilhelm Pfleging","Koji Sugioka" ], "editors": [ {"first" : "Rainer", "last" : "Kling"}, {"first" : "Wilhelm", "last" : "Pfleging"}, {"first" : "Koji", "last" : "Sugioka"} ], "abstract": "The comprehension of microhole formation during percussion drilling of metals using ultrashort laser pulses is still limited. The shape of a microhole can be impacted by factors like heat accumulation, the emergence of side channels, bending, and bulging. Understanding these defects is challenging due to constraints in conventional diagnostics. To address this issue, high-speed synchrotron X-ray imaging was employed to capture the spatial and temporal evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images reveal that heat accumulation leads to the creation of a melt film on the microhole walls, exhibiting dynamic fluctuations throughout the drilling process. Furthermore, a transversal widening or bulging of the microhole can be seen later in the process. Additionally, the emergence of side channels was observed in the region of maximum drilling depth, where the overall fluence on the microhole walls falls below the threshold fluence.", "eventtitle" : "LASE, Photonics West", "venue" : "San Francisco, California, United States", "bibtexKey": "henn2024unveiling" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/27240f95f2b10c0f59ce0e56439d863cd/ifsw", "tags" : [ "myown","ablation","x-ray","ultrashort","nondestructive","drilling","diagnostics","micromaterialprocessing","pulse","stainlesssteel","processmonitoring" ], "intraHash" : "7240f95f2b10c0f59ce0e56439d863cd", "interHash" : "bc55142d39b406391173f3bacf6629a2", "label" : "Unveiling laser percussion drilling in metals with ultrashort pulses: insights from high-speed synchrotron x-ray imaging on microhole formation and side channel phenomena", "user" : "ifsw", "description" : "", "date" : "2024-05-14 16:29:21", "changeDate" : "2024-05-14 16:29:21", "count" : 5, "pub-type": "presentation", "year": "2024", "url": "https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12873/1287309/Unveiling-laser-percussion-drilling-in-metals-with-ultrashort-pulses/10.1117/12.3003661.full", "author": [ "Manuel Henn","Lukas Schneller","Daniel Holder","Dennis Haasler","Marc Hummel","Felix Beckmann","Julian Moosmann","Christian Hagenlocher","Thomas Graf" ], "authors": [ {"first" : "Manuel", "last" : "Henn"}, {"first" : "Lukas", "last" : "Schneller"}, {"first" : "Daniel", "last" : "Holder"}, {"first" : "Dennis", "last" : "Haasler"}, {"first" : "Marc", "last" : "Hummel"}, {"first" : "Felix", "last" : "Beckmann"}, {"first" : "Julian", "last" : "Moosmann"}, {"first" : "Christian", "last" : "Hagenlocher"}, {"first" : "Thomas", "last" : "Graf"} ], "editor": [ "Rainer Kling","Wilhelm Pfleging","Koji Sugioka" ], "editors": [ {"first" : "Rainer", "last" : "Kling"}, {"first" : "Wilhelm", "last" : "Pfleging"}, {"first" : "Koji", "last" : "Sugioka"} ], "abstract": "The comprehension of microhole formation during percussion drilling of metals using ultrashort laser pulses is still limited. The shape of a microhole can be impacted by factors like heat accumulation, the emergence of side channels, bending, and bulging. Understanding these defects is challenging due to constraints in conventional diagnostics. To address this issue, high-speed synchrotron X-ray imaging was employed to capture the spatial and temporal evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images reveal that heat accumulation leads to the creation of a melt film on the microhole walls, exhibiting dynamic fluctuations throughout the drilling process. Furthermore, a transversal widening or bulging of the microhole can be seen later in the process. Additionally, the emergence of side channels was observed in the region of maximum drilling depth, where the overall fluence on the microhole walls falls below the threshold fluence.", "eventtitle" : "LASE, Photonics West", "venue" : "San Francisco, California, United States", "bibtexKey": "henn2024unveiling" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2d511c01e84df7afbf88f28aa5084e4bc/manuelhenn", "tags" : [ "ablation","diagnostics","drilling","micromaterialprocessing","myown","nondestructive","processmonitoring","stainlesssteel","ultrashortpulse","x-ray" ], "intraHash" : "d511c01e84df7afbf88f28aa5084e4bc", "interHash" : "56ffbc2b9fc009e155ec5ca0aec781e5", "label" : "The progress of microhole formation during laser percussion drilling of steel observed by highspeed synchrotron x-ray imaging", "user" : "manuelhenn", "description" : "", "date" : "2024-05-08 10:04:33", "changeDate" : "2024-05-08 10:04:33", "count" : 5, "pub-type": "inproceedings", "booktitle": "Lasers in Manufacturing Conference 2023","series": "Proc. LiM", "year": "2023", "url": "https://wlt.de/sites/default/files/2023-09/Contribution_223.pdf", "author": [ "Manuel Henn","Christian Hagenlocher","Daniel Holder","Daniel J. Förster","Rudolf Weber","Dennis Haasler","Marc Hummel","Alexander Olowinsky","Felix Beckmann","Julian Moosmann","Thomas Graf" ], "authors": [ {"first" : "Manuel", "last" : "Henn"}, {"first" : "Christian", "last" : "Hagenlocher"}, {"first" : "Daniel", "last" : "Holder"}, {"first" : "Daniel J.", "last" : "Förster"}, {"first" : "Rudolf", "last" : "Weber"}, {"first" : "Dennis", "last" : "Haasler"}, {"first" : "Marc", "last" : "Hummel"}, {"first" : "Alexander", "last" : "Olowinsky"}, {"first" : "Felix", "last" : "Beckmann"}, {"first" : "Julian", "last" : "Moosmann"}, {"first" : "Thomas", "last" : "Graf"} ], "abstract": "The formation of microholes during the percussion drilling of metals using ultrashort laser pulses remains poorly understood. The quality of a microhole can be affected by heat accumulation, the development of side channels, and microhole bulging due to plasma formation. Highspeed synchrotron X-ray imaging was applied to capture the space- and time-resolved evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images show that heat accumulation leads to the formation of a melt film on microhole walls, which dynamically fluctuates during drilling. Additionally, the formation of side channels was observed in the region of the maximum drilling depth where the overall fluence on the microhole walls drops below the threshold fluence. The experimentally captured quantities agree well with existing models and will significantly improve their prediction accuracy.", "eventtitle" : "Lasers in Manufacturing Conference", "venue" : "Munich, Germany", "bibtexKey": "henn2023progress" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2d511c01e84df7afbf88f28aa5084e4bc/ifsw", "tags" : [ "myown","ablation","x-ray","nondestructive","ultrashortpulse","drilling","diagnostics","micromaterialprocessing","stainlesssteel","processmonitoring" ], "intraHash" : "d511c01e84df7afbf88f28aa5084e4bc", "interHash" : "56ffbc2b9fc009e155ec5ca0aec781e5", "label" : "The progress of microhole formation during laser percussion drilling of steel observed by highspeed synchrotron x-ray imaging", "user" : "ifsw", "description" : "", "date" : "2024-05-08 10:04:33", "changeDate" : "2024-05-08 10:04:33", "count" : 5, "pub-type": "inproceedings", "booktitle": "Lasers in Manufacturing Conference 2023","series": "Proc. 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The quality of a microhole can be affected by heat accumulation, the development of side channels, and microhole bulging due to plasma formation. Highspeed synchrotron X-ray imaging was applied to capture the space- and time-resolved evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images show that heat accumulation leads to the formation of a melt film on microhole walls, which dynamically fluctuates during drilling. Additionally, the formation of side channels was observed in the region of the maximum drilling depth where the overall fluence on the microhole walls drops below the threshold fluence. The experimentally captured quantities agree well with existing models and will significantly improve their prediction accuracy.", "eventtitle" : "Lasers in Manufacturing Conference", "venue" : "Munich, Germany", "bibtexKey": "henn2023progress" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/289f76b3aa5320b1d6d6b2b84080c1475/manuelhenn", "tags" : [ "Ablation","Diagnostics","Drilling","MicroMaterialProcessing","NonDestructive","ProcessMonitoring","StainlessSteel","UltrashortPulse","X-ray","myown" ], "intraHash" : "89f76b3aa5320b1d6d6b2b84080c1475", "interHash" : "bc55142d39b406391173f3bacf6629a2", "label" : "Unveiling laser percussion drilling in metals with ultrashort pulses: insights from high-speed synchrotron x-ray imaging on microhole formation and side channel phenomena", "user" : "manuelhenn", "description" : "", "date" : "2024-05-07 23:12:02", "changeDate" : "2024-05-07 23:12:02", "count" : 5, "pub-type": "inproceedings", "booktitle": "Laser-based Micro- and Nanoprocessing XVIII","series": "Proc. 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The shape of a microhole can be impacted by factors like heat accumulation, the emergence of side channels, bending, and bulging. Understanding these defects is challenging due to constraints in conventional diagnostics. To address this issue, high-speed synchrotron X-ray imaging was employed to capture the spatial and temporal evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images reveal that heat accumulation leads to the creation of a melt film on the microhole walls, exhibiting dynamic fluctuations throughout the drilling process. Furthermore, a transversal widening or bulging of the microhole can be seen later in the process. Additionally, the emergence of side channels was observed in the region of maximum drilling depth, where the overall fluence on the microhole walls falls below the threshold fluence.", "venue" : "San Francisco, California, United States", "eventtitle" : "LASE, Photonics West", "doi" : "10.1117/12.3003661", "bibtexKey": "henn2024unveiling" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/289f76b3aa5320b1d6d6b2b84080c1475/ifsw", "tags" : [ "Drilling","myown","Diagnostics","Ablation","MicroMaterialProcessing","ProcessMonitoring","StainlessSteel","UltrashortPulse","NonDestructive","X-ray" ], "intraHash" : "89f76b3aa5320b1d6d6b2b84080c1475", "interHash" : "bc55142d39b406391173f3bacf6629a2", "label" : "Unveiling laser percussion drilling in metals with ultrashort pulses: insights from high-speed synchrotron x-ray imaging on microhole formation and side channel phenomena", "user" : "ifsw", "description" : "", "date" : "2024-05-07 23:12:02", "changeDate" : "2024-05-07 23:12:02", "count" : 5, "pub-type": "inproceedings", "booktitle": "Laser-based Micro- and Nanoprocessing XVIII","series": "Proc. SPIE","publisher":"SPIE", "year": "2024", "url": "http://dx.doi.org/10.1117/12.3003661", "author": [ "Manuel Henn","Lukas Schneller","Daniel Holder","Dennis Haasler","Marc Hummel","Felix Beckmann","Julian Moosmann","Christian Hagenlocher","Thomas Graf" ], "authors": [ {"first" : "Manuel", "last" : "Henn"}, {"first" : "Lukas", "last" : "Schneller"}, {"first" : "Daniel", "last" : "Holder"}, {"first" : "Dennis", "last" : "Haasler"}, {"first" : "Marc", "last" : "Hummel"}, {"first" : "Felix", "last" : "Beckmann"}, {"first" : "Julian", "last" : "Moosmann"}, {"first" : "Christian", "last" : "Hagenlocher"}, {"first" : "Thomas", "last" : "Graf"} ], "editor": [ "Rainer Kling","Wilhelm Pfleging","Koji Sugioka" ], "editors": [ {"first" : "Rainer", "last" : "Kling"}, {"first" : "Wilhelm", "last" : "Pfleging"}, {"first" : "Koji", "last" : "Sugioka"} ], "volume": "12873","number": "1287309-1","abstract": "The comprehension of microhole formation during percussion drilling of metals using ultrashort laser pulses is still limited. The shape of a microhole can be impacted by factors like heat accumulation, the emergence of side channels, bending, and bulging. Understanding these defects is challenging due to constraints in conventional diagnostics. To address this issue, high-speed synchrotron X-ray imaging was employed to capture the spatial and temporal evolution of the microhole shape during laser percussion drilling of stainless steel. The recorded images reveal that heat accumulation leads to the creation of a melt film on the microhole walls, exhibiting dynamic fluctuations throughout the drilling process. Furthermore, a transversal widening or bulging of the microhole can be seen later in the process. Additionally, the emergence of side channels was observed in the region of maximum drilling depth, where the overall fluence on the microhole walls falls below the threshold fluence.", "venue" : "San Francisco, California, United States", "eventtitle" : "LASE, Photonics West", "doi" : "10.1117/12.3003661", "bibtexKey": "henn2024unveiling" } ] }