{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/127504"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/127504","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Novel post-processing methods on additively manufactured thermal devices for high performance cooling","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-12-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-12-01","abstract_has_math":false,"creators":["Uvodich, Kevin"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Miljkovic, Nenad","Haran, Kiruba","Cai, Lili","Zhang, Winston"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2024,"date_issued":"2024-12","date_published":"2024-12","updated_at":"2026-07-22T22:25:04Z","subjects":["Additive Manufacturing","Etching","Post-processing","Heat Exchangers","Heatsinks","Etch Rates","Ct Scanning","Roughness","Flow Etching","Microchannels","Dross"],"languages":["en","eng"],"rights":["Copyright 2024 Kevin Uvodich"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/127504","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Miljkovic, Nenad","Haran, Kiruba","Cai, Lili","Zhang, Winston"]},{"key":"dc:creator","label":"Author","values":["Uvodich, Kevin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2024-12","2024-12-06"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Additive Manufacturing","Etching","Post-processing","Heat Exchangers","Heatsinks","Etch Rates","Ct Scanning","Roughness","Flow Etching","Microchannels","Dross"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2024 Kevin Uvodich"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/127504"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-12-01","The student, Kevin Uvodich, accepted the attached license on 2024-12-05 at 20:11.","The student, Kevin Uvodich, submitted this Dissertation for approval on 2024-12-05 at 20:28.","This Dissertation was approved for publication on 2024-12-06 at 14:45.","DSpace SAF Submission Ingestion Package generated from Vireo submission #21519 on 2025-03-28 at 14:56:45","Additive Manufacturing (AM) is becoming an established technology with high impact. The invention of Direct Metal Laser Sintering (DMLS) to produce solid metal parts layer by layer from a powder has altered the landscape of many industries, where increased design flexibility allows for more innovative designs. This creates opportunities in thermal management technology, which is a bottleneck for many systems such as computer and power electronics. Microchannel heat exchangers are a potential solution in many cases, such as conformal cooling applications of system components with large heat fluxes. However, several challenges with metal AM technology still limit its usefulness in practice. This work addresses the challenges and offers solutions using novel post-processing methods coupled with non-destructive analysis, providing a framework for reliable implementation of the suggested methods. Using a chemical flow etching process, metal AM parts are post-processed and evaluated in three different contexts. First, a method for resolving failed DMLS microchannels is demonstrated using chemical flow etching to clear obstructions and remove surface roughness. Experiments show clear trends of microchannel failure likelihood and severity increasing with parameters such as decreasing channel diameter, increasing aspect ratio, and increasing surface overhang. The post-process enables the creation of passable microchannels that initially fail as printed. X-ray Computed Tomography (CT scanning) is utilized as a powerful non-destructive tool to support analysis on the effects of the post-process, by revealing the extent and nature of microchannel obstructions. With the utility of flow etching established, the effects of such a process on the various forms of surface roughness present with metal AM are studied and quantified, as well as the effects on thermal-hydraulic performance. In the second study, single microchannel and parallel microchannel AlSi10Mg samples are characterized and measured using CT scanning, with thermal-hydraulic performance measured experimentally before and after post-processing. For the third context, the post-process is studied for positive feature creation, using the etching to achieve thin features below current metal AM capabilities. The influence of hydrodynamics, geometry, concentration, and temperature on etch rates of internal features during a flow etch are measured and compared to predictions. This research lays the groundwork for chemical flow etching to be used in metal AM post processing to elevate the technology and push the limits of what is possible. It also highlights key areas of importance for future development so the post-process can be applied reliably and consistently in a variety of situations."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Novel post-processing methods on additively manufactured thermal devices for high performance cooling"]}]}],"canonical_facts":{"dc:contributor":["Miljkovic, Nenad","Haran, Kiruba","Cai, Lili","Zhang, Winston"],"dc:creator":["Uvodich, Kevin"],"dc:date":["2024-12","2024-12-06"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-12-01","The student, Kevin Uvodich, accepted the attached license on 2024-12-05 at 20:11.","The student, Kevin Uvodich, submitted this Dissertation for approval on 2024-12-05 at 20:28.","This Dissertation was approved for publication on 2024-12-06 at 14:45.","DSpace SAF Submission Ingestion Package generated from Vireo submission #21519 on 2025-03-28 at 14:56:45","Additive Manufacturing (AM) is becoming an established technology with high impact. The invention of Direct Metal Laser Sintering (DMLS) to produce solid metal parts layer by layer from a powder has altered the landscape of many industries, where increased design flexibility allows for more innovative designs. This creates opportunities in thermal management technology, which is a bottleneck for many systems such as computer and power electronics. Microchannel heat exchangers are a potential solution in many cases, such as conformal cooling applications of system components with large heat fluxes. However, several challenges with metal AM technology still limit its usefulness in practice. This work addresses the challenges and offers solutions using novel post-processing methods coupled with non-destructive analysis, providing a framework for reliable implementation of the suggested methods. Using a chemical flow etching process, metal AM parts are post-processed and evaluated in three different contexts. First, a method for resolving failed DMLS microchannels is demonstrated using chemical flow etching to clear obstructions and remove surface roughness. Experiments show clear trends of microchannel failure likelihood and severity increasing with parameters such as decreasing channel diameter, increasing aspect ratio, and increasing surface overhang. The post-process enables the creation of passable microchannels that initially fail as printed. X-ray Computed Tomography (CT scanning) is utilized as a powerful non-destructive tool to support analysis on the effects of the post-process, by revealing the extent and nature of microchannel obstructions. With the utility of flow etching established, the effects of such a process on the various forms of surface roughness present with metal AM are studied and quantified, as well as the effects on thermal-hydraulic performance. In the second study, single microchannel and parallel microchannel AlSi10Mg samples are characterized and measured using CT scanning, with thermal-hydraulic performance measured experimentally before and after post-processing. For the third context, the post-process is studied for positive feature creation, using the etching to achieve thin features below current metal AM capabilities. The influence of hydrodynamics, geometry, concentration, and temperature on etch rates of internal features during a flow etch are measured and compared to predictions. This research lays the groundwork for chemical flow etching to be used in metal AM post processing to elevate the technology and push the limits of what is possible. It also highlights key areas of importance for future development so the post-process can be applied reliably and consistently in a variety of situations."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/127504"],"dc:language":["en","eng"],"dc:rights":["Copyright 2024 Kevin Uvodich"],"dc:subject":["Additive Manufacturing","Etching","Post-processing","Heat Exchangers","Heatsinks","Etch Rates","Ct Scanning","Roughness","Flow Etching","Microchannels","Dross"],"dc:title":["Novel post-processing methods on additively manufactured thermal devices for high performance cooling"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:04Z"}