{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/132510"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/132510","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Irradiation effects on geopolymer and additively manufactured 316H stainless steel and porosity in equine hoof wall","abstract":"This Ph.D. dissertation research investigated three classes of materials designed for extreme environments. They include metakaolin-based geopolymers for nuclear shielding, additively manufactured (AM) 316H stainless steel (SS) for radiation resistance, and equine hoof walls serving as bioinspiration for impact-resistant materials designs. First, I explored a potassium-based geopolymer implanted with Ti+ ions to simulate neutron irradiation as a concrete alternative for nuclear facilities. Post-irradiation, the geopolymer showed a 90% increase in microhardness, a 46% rise in reduced modulus, and a 23% decrease in contact depth. Surface cracking was observed, attributed to ion implantation and reduced water content, highlighting its potential for shielding applications with further optimization. Next, we studied the irradiation response of AM 316H SS, produced via laser powder bed fusion, compared to conventionally manufactured SS under simulated irradiation conditions using 0.5 MeV H+ ions. Multiscale characterization showed AM SS exhibited higher initial dislocation densities, reduced microstrain at lower doses (0.6 dpa), and more stable mechanical behavior under irradiation than conventional SS. Microhardness testing revealed a gradual response in AM SS, while tensile tests indicated reduced hardening and strength. The surface analysis highlighted distinct pore morphologies and stable elemental composition in AM SS, contrasting the significant surface deterioration in conventional SS. These findings demonstrate AM 316H SS’s superior microhardness, microstructural integrity, and radiation resistance, underscoring its suitability for irradiated environments. Molecular dynamics simulations allowed us to explore the influence of porous microstructures on AM 316H SS’s radiation resistance. By investigating varying pore configurations (1 to 30,720 pores) and primary knock-on atom (PKA) energies (5, 10, and 15 keV), this modeling revealed that defect numbers increased significantly with higher pore counts. The 6-pore configuration exhibited optimal irradiation resistance, while high pore densities altered dislocation mechanisms. The results provide critical insights into the enhanced radiation resistance observed in AM materials. Finally, we investigated equine hoof walls using micro-computed tomography (μ-CT) and serial block-face scanning electron microscopy (SBF-SEM). The discovery of nano-sized pores within the tubule wall explained higher porosity values observed via helium pycnometer. This characterization of the hoof wall structure can inform the design of energy-absorbing materials. This dissertation advances the understanding of materials’ behavior under extreme conditions, offering insights into radiation-resistant materials and bioinspired designs for improved performance in nuclear and structural applications.","abstract_html":"This Ph.D. dissertation research investigated three classes of materials designed for extreme environments. They include metakaolin-based geopolymers for nuclear shielding, additively manufactured (AM) 316H stainless steel (SS) for radiation resistance, and equine hoof walls serving as bioinspiration for impact-resistant materials designs. First, I explored a potassium-based geopolymer implanted with Ti+ ions to simulate neutron irradiation as a concrete alternative for nuclear facilities. Post-irradiation, the geopolymer showed a 90% increase in microhardness, a 46% rise in reduced modulus, and a 23% decrease in contact depth. Surface cracking was observed, attributed to ion implantation and reduced water content, highlighting its potential for shielding applications with further optimization. Next, we studied the irradiation response of AM 316H SS, produced via laser powder bed fusion, compared to conventionally manufactured SS under simulated irradiation conditions using 0.5 MeV H+ ions. Multiscale characterization showed AM SS exhibited higher initial dislocation densities, reduced microstrain at lower doses (0.6 dpa), and more stable mechanical behavior under irradiation than conventional SS. Microhardness testing revealed a gradual response in AM SS, while tensile tests indicated reduced hardening and strength. The surface analysis highlighted distinct pore morphologies and stable elemental composition in AM SS, contrasting the significant surface deterioration in conventional SS. These findings demonstrate AM 316H SS’s superior microhardness, microstructural integrity, and radiation resistance, underscoring its suitability for irradiated environments. Molecular dynamics simulations allowed us to explore the influence of porous microstructures on AM 316H SS’s radiation resistance. By investigating varying pore configurations (1 to 30,720 pores) and primary knock-on atom (PKA) energies (5, 10, and 15 keV), this modeling revealed that defect numbers increased significantly with higher pore counts. The 6-pore configuration exhibited optimal irradiation resistance, while high pore densities altered dislocation mechanisms. The results provide critical insights into the enhanced radiation resistance observed in AM materials. Finally, we investigated equine hoof walls using micro-computed tomography (μ-CT) and serial block-face scanning electron microscopy (SBF-SEM). The discovery of nano-sized pores within the tubule wall explained higher porosity values observed via helium pycnometer. This characterization of the hoof wall structure can inform the design of energy-absorbing materials. This dissertation advances the understanding of materials’ behavior under extreme conditions, offering insights into radiation-resistant materials and bioinspired designs for improved performance in nuclear and structural applications.","abstract_has_math":false,"creators":["Mahrous, Mahmoud A."],"institution":"University of Illinois Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Civil Engineering","degree_department":null,"school":null,"contributors":["Jasiuk, Iwona M","Popovics, John","Henschen, Jacob","Shoemaker, Daniel"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-12","date_published":"2025-12","updated_at":"2026-07-22T22:25:07Z","subjects":["Extreme environments","radiation resistance","additive manufacturing","molecular dynamics simulations","bioinspired materials","geopolymers","316H stainless steel","ion irradiation","porous microstructures","multiscale characterization"],"languages":["en"],"rights":["No copyright needed"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/132510","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Jasiuk, Iwona M","Popovics, John","Henschen, Jacob","Shoemaker, Daniel"]},{"key":"dc:creator","label":"Author","values":["Mahrous, Mahmoud A."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-12","2025-11-26"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil 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 Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Extreme environments","radiation resistance","additive manufacturing","molecular dynamics simulations","bioinspired materials","geopolymers","316H stainless steel","ion irradiation","porous microstructures","multiscale characterization"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["No copyright needed"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/132510"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This Ph.D. dissertation research investigated three classes of materials designed for extreme environments. They include metakaolin-based geopolymers for nuclear shielding, additively manufactured (AM) 316H stainless steel (SS) for radiation resistance, and equine hoof walls serving as bioinspiration for impact-resistant materials designs. First, I explored a potassium-based geopolymer implanted with Ti+ ions to simulate neutron irradiation as a concrete alternative for nuclear facilities. Post-irradiation, the geopolymer showed a 90% increase in microhardness, a 46% rise in reduced modulus, and a 23% decrease in contact depth. Surface cracking was observed, attributed to ion implantation and reduced water content, highlighting its potential for shielding applications with further optimization. Next, we studied the irradiation response of AM 316H SS, produced via laser powder bed fusion, compared to conventionally manufactured SS under simulated irradiation conditions using 0.5 MeV H+ ions. Multiscale characterization showed AM SS exhibited higher initial dislocation densities, reduced microstrain at lower doses (0.6 dpa), and more stable mechanical behavior under irradiation than conventional SS. Microhardness testing revealed a gradual response in AM SS, while tensile tests indicated reduced hardening and strength. The surface analysis highlighted distinct pore morphologies and stable elemental composition in AM SS, contrasting the significant surface deterioration in conventional SS. These findings demonstrate AM 316H SS’s superior microhardness, microstructural integrity, and radiation resistance, underscoring its suitability for irradiated environments. Molecular dynamics simulations allowed us to explore the influence of porous microstructures on AM 316H SS’s radiation resistance. By investigating varying pore configurations (1 to 30,720 pores) and primary knock-on atom (PKA) energies (5, 10, and 15 keV), this modeling revealed that defect numbers increased significantly with higher pore counts. The 6-pore configuration exhibited optimal irradiation resistance, while high pore densities altered dislocation mechanisms. The results provide critical insights into the enhanced radiation resistance observed in AM materials. Finally, we investigated equine hoof walls using micro-computed tomography (μ-CT) and serial block-face scanning electron microscopy (SBF-SEM). The discovery of nano-sized pores within the tubule wall explained higher porosity values observed via helium pycnometer. This characterization of the hoof wall structure can inform the design of energy-absorbing materials. This dissertation advances the understanding of materials’ behavior under extreme conditions, offering insights into radiation-resistant materials and bioinspired designs for improved performance in nuclear and structural applications.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2026-02-19 without embargo terms","The student, Mahmoud Mahrous, accepted the attached license on 2025-11-19 at 11:40.","The student, Mahmoud Mahrous, submitted this Dissertation for approval on 2025-11-19 at 11:49.","This Dissertation was approved for publication on 2025-11-26 at 13:17.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22899 on 2026-02-19 at 18:25:02"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Irradiation effects on geopolymer and additively manufactured 316H stainless steel and porosity in equine hoof wall"]}]}],"canonical_facts":{"dc:contributor":["Jasiuk, Iwona M","Popovics, John","Henschen, Jacob","Shoemaker, Daniel"],"dc:creator":["Mahrous, Mahmoud A."],"dc:date":["2025-12","2025-11-26"],"dc:description":["This Ph.D. dissertation research investigated three classes of materials designed for extreme environments. They include metakaolin-based geopolymers for nuclear shielding, additively manufactured (AM) 316H stainless steel (SS) for radiation resistance, and equine hoof walls serving as bioinspiration for impact-resistant materials designs. First, I explored a potassium-based geopolymer implanted with Ti+ ions to simulate neutron irradiation as a concrete alternative for nuclear facilities. Post-irradiation, the geopolymer showed a 90% increase in microhardness, a 46% rise in reduced modulus, and a 23% decrease in contact depth. Surface cracking was observed, attributed to ion implantation and reduced water content, highlighting its potential for shielding applications with further optimization. Next, we studied the irradiation response of AM 316H SS, produced via laser powder bed fusion, compared to conventionally manufactured SS under simulated irradiation conditions using 0.5 MeV H+ ions. Multiscale characterization showed AM SS exhibited higher initial dislocation densities, reduced microstrain at lower doses (0.6 dpa), and more stable mechanical behavior under irradiation than conventional SS. Microhardness testing revealed a gradual response in AM SS, while tensile tests indicated reduced hardening and strength. The surface analysis highlighted distinct pore morphologies and stable elemental composition in AM SS, contrasting the significant surface deterioration in conventional SS. These findings demonstrate AM 316H SS’s superior microhardness, microstructural integrity, and radiation resistance, underscoring its suitability for irradiated environments. Molecular dynamics simulations allowed us to explore the influence of porous microstructures on AM 316H SS’s radiation resistance. By investigating varying pore configurations (1 to 30,720 pores) and primary knock-on atom (PKA) energies (5, 10, and 15 keV), this modeling revealed that defect numbers increased significantly with higher pore counts. The 6-pore configuration exhibited optimal irradiation resistance, while high pore densities altered dislocation mechanisms. The results provide critical insights into the enhanced radiation resistance observed in AM materials. Finally, we investigated equine hoof walls using micro-computed tomography (μ-CT) and serial block-face scanning electron microscopy (SBF-SEM). The discovery of nano-sized pores within the tubule wall explained higher porosity values observed via helium pycnometer. This characterization of the hoof wall structure can inform the design of energy-absorbing materials. This dissertation advances the understanding of materials’ behavior under extreme conditions, offering insights into radiation-resistant materials and bioinspired designs for improved performance in nuclear and structural applications.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2026-02-19 without embargo terms","The student, Mahmoud Mahrous, accepted the attached license on 2025-11-19 at 11:40.","The student, Mahmoud Mahrous, submitted this Dissertation for approval on 2025-11-19 at 11:49.","This Dissertation was approved for publication on 2025-11-26 at 13:17.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22899 on 2026-02-19 at 18:25:02"],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/132510"],"dc:language":["en"],"dc:rights":["No copyright needed"],"dc:subject":["Extreme environments","radiation resistance","additive manufacturing","molecular dynamics simulations","bioinspired materials","geopolymers","316H stainless steel","ion irradiation","porous microstructures","multiscale characterization"],"dc:title":["Irradiation effects on geopolymer and additively manufactured 316H stainless steel and porosity in equine hoof wall"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Civil Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:07Z"}