Metal droplet-based 3D printing is a popular technique used for creating complex structures and multi-material components. However, accuracy is a significant challenge in this process due to complex thermal and dynamic behaviors that can negatively affect the final workpiece. To improve accuracy, the interactions between droplet impact dynamics and the deposition process of the droplets must be understood and ultimately controlled. In this thesis, I describe the optimization and implementation of an experimental setup for generating droplets of tin and for studying their impact dynamics. In particular, this thesis explains how an existing preliminary droplet generator was modified to produce single droplets and how oxidation of the tin was avoided. The problem of continuous droplet dropping was solved by installing a vent hole which can be controlled by a flow-adjustment valve that can release excess gas to reduce the pressure given to the heater chamber. Another critical factor in the experiment was preventing the oxidation of tin at high temperatures. To avoid this, air was evacuated from the environmental chamber and instead flushed by nitrogen. This work details how to check and modify the system leakage and redesign the generator. Overall, the modifications and improvements aimed to optimize the process of generating droplets for future research. I will conclude by presenting preliminary experiments on droplet impact and solidification dynamics, which will lay the groundwork for future researchers to study the coupling of impact, heat transfer, and solidification dynamics in more detail.
","abstract_html":"<p>Metal droplet-based 3D printing is a popular technique used for creating complex structures and multi-material components. However, accuracy is a significant challenge in this process due to complex thermal and dynamic behaviors that can negatively affect the final workpiece. To improve accuracy, the interactions between droplet impact dynamics and the deposition process of the droplets must be understood and ultimately controlled. In this thesis, I describe the optimization and implementation of an experimental setup for generating droplets of tin and for studying their impact dynamics. In particular, this thesis explains how an existing preliminary droplet generator was modified to produce single droplets and how oxidation of the tin was avoided. The problem of continuous droplet dropping was solved by installing a vent hole which can be controlled by a flow-adjustment valve that can release excess gas to reduce the pressure given to the heater chamber. Another critical factor in the experiment was preventing the oxidation of tin at high temperatures. To avoid this, air was evacuated from the environmental chamber and instead flushed by nitrogen. This work details how to check and modify the system leakage and redesign the generator. Overall, the modifications and improvements aimed to optimize the process of generating droplets for future research. I will conclude by presenting preliminary experiments on droplet impact and solidification dynamics, which will lay the groundwork for future researchers to study the coupling of impact, heat transfer, and solidification dynamics in more detail.</p>","abstract_has_math":false,"creators":["Xu, Xitong"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Mechanical Engineering & Materials Science","degree_department":null,"school":null,"contributors":["Patricia Weisensee, Mechanical Engineering & Materials Science","Patricia Weisensee Xianglin Li J. Mark Meacham"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-04-01T07:00:00Z","date_published":"2023-04-01T07:00:00Z","updated_at":"2026-07-24T06:13:40Z","subjects":["Engineering"],"languages":["English (en)"],"rights":["I have not registered my thesis with the U.S. Copyright Office, and do not intend to."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://openscholarship.wustl.edu/eng_etds/839"],"render_values":[{"text":"https://openscholarship.wustl.edu/eng_etds/839","href":"https://openscholarship.wustl.edu/eng_etds/839","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.7936/64vx-2898","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Patricia Weisensee, Mechanical Engineering & Materials Science","Patricia Weisensee Xianglin Li J. Mark Meacham"]},{"key":"dc:creator","label":"Author","values":["Xu, Xitong"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2026-04-22T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering & Materials Science","McKelvey School of Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English (en)"]},{"key":"dc:rights","label":"Dc Rights","values":["I have not registered my thesis with the U.S. Copyright Office, and do not intend to."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://doi.org/10.7936/64vx-2898","https://openscholarship.wustl.edu/eng_etds/839"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Metal droplet-based 3D printing is a popular technique used for creating complex structures and multi-material components. However, accuracy is a significant challenge in this process due to complex thermal and dynamic behaviors that can negatively affect the final workpiece. To improve accuracy, the interactions between droplet impact dynamics and the deposition process of the droplets must be understood and ultimately controlled. In this thesis, I describe the optimization and implementation of an experimental setup for generating droplets of tin and for studying their impact dynamics. In particular, this thesis explains how an existing preliminary droplet generator was modified to produce single droplets and how oxidation of the tin was avoided. The problem of continuous droplet dropping was solved by installing a vent hole which can be controlled by a flow-adjustment valve that can release excess gas to reduce the pressure given to the heater chamber. Another critical factor in the experiment was preventing the oxidation of tin at high temperatures. To avoid this, air was evacuated from the environmental chamber and instead flushed by nitrogen. This work details how to check and modify the system leakage and redesign the generator. Overall, the modifications and improvements aimed to optimize the process of generating droplets for future research. I will conclude by presenting preliminary experiments on droplet impact and solidification dynamics, which will lay the groundwork for future researchers to study the coupling of impact, heat transfer, and solidification dynamics in more detail.
"]},{"key":"dc:title","label":"Title","values":["Development of a Metal Droplet Generator for Studying Impact Dynamics"]}]}],"canonical_facts":{"dc:contributor":["Patricia Weisensee, Mechanical Engineering & Materials Science","Patricia Weisensee Xianglin Li J. Mark Meacham"],"dc:creator":["Xu, Xitong"],"dc:date.available":["2026-04-22T07:00:00Z"],"dc:description.abstract":["Metal droplet-based 3D printing is a popular technique used for creating complex structures and multi-material components. However, accuracy is a significant challenge in this process due to complex thermal and dynamic behaviors that can negatively affect the final workpiece. To improve accuracy, the interactions between droplet impact dynamics and the deposition process of the droplets must be understood and ultimately controlled. In this thesis, I describe the optimization and implementation of an experimental setup for generating droplets of tin and for studying their impact dynamics. In particular, this thesis explains how an existing preliminary droplet generator was modified to produce single droplets and how oxidation of the tin was avoided. The problem of continuous droplet dropping was solved by installing a vent hole which can be controlled by a flow-adjustment valve that can release excess gas to reduce the pressure given to the heater chamber. Another critical factor in the experiment was preventing the oxidation of tin at high temperatures. To avoid this, air was evacuated from the environmental chamber and instead flushed by nitrogen. This work details how to check and modify the system leakage and redesign the generator. Overall, the modifications and improvements aimed to optimize the process of generating droplets for future research. I will conclude by presenting preliminary experiments on droplet impact and solidification dynamics, which will lay the groundwork for future researchers to study the coupling of impact, heat transfer, and solidification dynamics in more detail.
"],"dc:identifier":["https://doi.org/10.7936/64vx-2898","https://openscholarship.wustl.edu/eng_etds/839"],"dc:language":["English (en)"],"dc:rights":["I have not registered my thesis with the U.S. Copyright Office, and do not intend to."],"dc:subject":["Engineering"],"dc:title":["Development of a Metal Droplet Generator for Studying Impact Dynamics"],"thesis:degree_discipline":["Mechanical Engineering & Materials Science","McKelvey School of Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T06:13:40Z"}