{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/102780"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/102780","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"3-D Printing, Characterizing and Evaluating the Mechanical Properties of 316L Stainless Steel Materials with Gradient Microstructure","abstract":"Making gradient in the microstructure of metals is proven to be a superior method for improving their mechanical properties. In this research, we 3D print, characterize and evaluate the mechanical properties of 316L Stainless Steel with a gradient in their microstructure. During 3D printing, the gradient in the microstructure is created by tailoring the processing parameters (hatch spacing, scanning speed, and laser power and scanning speed) of the Selective Laser Melting (SLM). The Materials with Graded Microstructure (MGMs) are characterized by optical and scanning electron microscopy (SEM). Image processing framework is utilized to reveal the distribution of cells and melt pools shapes and sizes in the volume of the material when the processing parameters change. It is shown that the laser power, scanning speed and the hatch spacing have a more significant effect on the size and shape of cells and melt pools compared to the speed. Multiple Dog bones are 3D printed with a microstructure that has smaller features (cells and melt polls) at the edges of the structure compared to the center. Tensile and fatigue tests are performed and compared for samples with constant and graded microstructures.","abstract_html":"Making gradient in the microstructure of metals is proven to be a superior method for improving their mechanical properties. In this research, we 3D print, characterize and evaluate the mechanical properties of 316L Stainless Steel with a gradient in their microstructure. During 3D printing, the gradient in the microstructure is created by tailoring the processing parameters (hatch spacing, scanning speed, and laser power and scanning speed) of the Selective Laser Melting (SLM). The Materials with Graded Microstructure (MGMs) are characterized by optical and scanning electron microscopy (SEM). Image processing framework is utilized to reveal the distribution of cells and melt pools shapes and sizes in the volume of the material when the processing parameters change. It is shown that the laser power, scanning speed and the hatch spacing have a more significant effect on the size and shape of cells and melt pools compared to the speed. Multiple Dog bones are 3D printed with a microstructure that has smaller features (cells and melt polls) at the edges of the structure compared to the center. Tensile and fatigue tests are performed and compared for samples with constant and graded microstructures.","abstract_has_math":false,"creators":["Stephen, Juanita Peche"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mechanical Engineering","degree_department":"Mechanical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Mirzaeifar, Reza"],"committee_members":["Acar, Pinar","Ranganathan, Shivakumar"],"year":2021,"date_issued":"2021-03-24","date_published":"2021-03-24","updated_at":"2026-07-22T22:20:16Z","subjects":["Selective Laser Melting","Material with Graded Microstructure","316L Stainless Steel","Mechanical Properties","Equiaxial Cellular Structure","3-D Printing","Laser Power","Scanning Speed","Hatch Spacing"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:29481"],"render_values":[{"text":"vt_gsexam:29481","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/102780","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Mirzaeifar, Reza"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Acar, Pinar","Ranganathan, Shivakumar"]},{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Stephen, Juanita Peche"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2021-03-25T08:00:24Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2021-03-25T08:00:24Z"]},{"key":"dc:date.issued","label":"Date","values":["2021-03-24"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Selective Laser Melting","Material with Graded Microstructure","316L Stainless Steel","Mechanical Properties","Equiaxial Cellular Structure","3-D Printing","Laser Power","Scanning Speed","Hatch Spacing"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:29481"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/102780"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Making gradient in the microstructure of metals is proven to be a superior method for improving their mechanical properties. In this research, we 3D print, characterize and evaluate the mechanical properties of 316L Stainless Steel with a gradient in their microstructure. During 3D printing, the gradient in the microstructure is created by tailoring the processing parameters (hatch spacing, scanning speed, and laser power and scanning speed) of the Selective Laser Melting (SLM). The Materials with Graded Microstructure (MGMs) are characterized by optical and scanning electron microscopy (SEM). Image processing framework is utilized to reveal the distribution of cells and melt pools shapes and sizes in the volume of the material when the processing parameters change. It is shown that the laser power, scanning speed and the hatch spacing have a more significant effect on the size and shape of cells and melt pools compared to the speed. Multiple Dog bones are 3D printed with a microstructure that has smaller features (cells and melt polls) at the edges of the structure compared to the center. Tensile and fatigue tests are performed and compared for samples with constant and graded microstructures."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["The mechanical performance of Selective Laser Melting (SLM) fabricated materials is an important topic in research. Strengthening the performance of these materials can be achieved through implementing a gradient within the microstructure, referred to as Materials with Graded Microstructure (MGMs). A complicated microstructure can weaken the microstructure, and this can be resolved by optimizing the microstructure during SLM 3D printing, in which the processing parameters are tailored. In this study, the mechanical properties of these MGMs were characterized and evaluated. The gradient in these materials were created by modifying SLM process parameters (scanning speed, hatch spacing, and laser power and scanning speed) during the build. Optical and scanning electron microscopy (SEM) was used to characterize these the microstructure of these MGMs, and image processing was used to examine the distribution of cells and melt pools characteristics throughout the region where the processing parameters changed. This investigation shows that laser power, scanning speed, and hatch spacing have a direct effect on the size and shape of the cells and melt pools, compared to scanning speed, which shows an effect on melt pools. Dog bone structures are 3-D printed with a graded microstructure that has small cells and melt pools at the edges, compared to the center, by changing the laser power and scanning speed. Tensile and fatigue analysis are performed and compared for samples with constant and graded microstructures, which reveal that the mechanical properties of the MGMs perform similar to the parameter at the edges, but differently in fracture mechanics."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["3-D Printing, Characterizing and Evaluating the Mechanical Properties of 316L Stainless Steel Materials with Gradient Microstructure"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Mirzaeifar, Reza"],"dc:contributor.committeemember":["Acar, Pinar","Ranganathan, Shivakumar"],"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Stephen, Juanita Peche"],"dc:date.accessioned":["2021-03-25T08:00:24Z"],"dc:date.available":["2021-03-25T08:00:24Z"],"dc:date.issued":["2021-03-24"],"dc:description.abstract":["Making gradient in the microstructure of metals is proven to be a superior method for improving their mechanical properties. In this research, we 3D print, characterize and evaluate the mechanical properties of 316L Stainless Steel with a gradient in their microstructure. During 3D printing, the gradient in the microstructure is created by tailoring the processing parameters (hatch spacing, scanning speed, and laser power and scanning speed) of the Selective Laser Melting (SLM). The Materials with Graded Microstructure (MGMs) are characterized by optical and scanning electron microscopy (SEM). Image processing framework is utilized to reveal the distribution of cells and melt pools shapes and sizes in the volume of the material when the processing parameters change. It is shown that the laser power, scanning speed and the hatch spacing have a more significant effect on the size and shape of cells and melt pools compared to the speed. Multiple Dog bones are 3D printed with a microstructure that has smaller features (cells and melt polls) at the edges of the structure compared to the center. Tensile and fatigue tests are performed and compared for samples with constant and graded microstructures."],"dc:description.abstractgeneral":["The mechanical performance of Selective Laser Melting (SLM) fabricated materials is an important topic in research. Strengthening the performance of these materials can be achieved through implementing a gradient within the microstructure, referred to as Materials with Graded Microstructure (MGMs). A complicated microstructure can weaken the microstructure, and this can be resolved by optimizing the microstructure during SLM 3D printing, in which the processing parameters are tailored. In this study, the mechanical properties of these MGMs were characterized and evaluated. The gradient in these materials were created by modifying SLM process parameters (scanning speed, hatch spacing, and laser power and scanning speed) during the build. Optical and scanning electron microscopy (SEM) was used to characterize these the microstructure of these MGMs, and image processing was used to examine the distribution of cells and melt pools characteristics throughout the region where the processing parameters changed. This investigation shows that laser power, scanning speed, and hatch spacing have a direct effect on the size and shape of the cells and melt pools, compared to scanning speed, which shows an effect on melt pools. Dog bone structures are 3-D printed with a graded microstructure that has small cells and melt pools at the edges, compared to the center, by changing the laser power and scanning speed. Tensile and fatigue analysis are performed and compared for samples with constant and graded microstructures, which reveal that the mechanical properties of the MGMs perform similar to the parameter at the edges, but differently in fracture mechanics."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:29481"],"dc:identifier.uri":["http://hdl.handle.net/10919/102780"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Selective Laser Melting","Material with Graded Microstructure","316L Stainless Steel","Mechanical Properties","Equiaxial Cellular Structure","3-D Printing","Laser Power","Scanning Speed","Hatch Spacing"],"dc:title":["3-D Printing, Characterizing and Evaluating the Mechanical Properties of 316L Stainless Steel Materials with Gradient Microstructure"],"dc:type":["Thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:16Z"}