Development of friction stir welding on large multi-welded components : residual stress, distortion, and crystallographic texture in lap joints of aluminum alloys
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Sabry, Nicholas
issued: 2024-08-01T20:08:50Z
issued: 2024
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: With the growing demand for increased battery capacity and performance, a corresponding requirement for adequate cooling of the battery cells has developed. This situation requires an efficient design of coolant channels in battery trays. The battery tray houses the cells and regulates their temperature, optimizing the distance per battery kilogram. The coolant channels in the battery tray require high-pressure die casting (HPDC) to create. However, the HPDC process is limited, and enclosed geometries for coolant flow cannot be created. Therefore, the coolant channels must be sealed with thin aluminum plates post-casting. A liquid seal is created by joining the aluminum plates to the HPDC component utilizing friction stir welding (FSW). FSW is an industry-emerging solid-state joining process by which its inherent nature overcomes many problems associated with fusion welding aluminum. These problems are due to aluminum's high-melting point oxide layer, high thermal conductivity, solidification shrinkage, and high solubility of hydrogen and other gases in the molten state, which are not an issue with FSW as the material being welded does not melt, and the brittle oxide layer breaks with the torsion of the tool intrinsically overcoming many problems related to fusion welding of aluminum. Nevertheless, the FSW welding operation leads to the development of residual stress, which compounds into a significant amount of distortion, specifically in multi-welded components, leading to expensive downstream straightening processes to restore the pre-weld geometry, which may or may not further increase residual stress. Residual stress, exceeding the stress limit of the battery tray during operation, can compromise the battery-cell housing and risk the vehicle's safety. Hence, understanding residual stress formation is vital for design, safety, service life longevity, and distortion control. Experiments utilizing neutron diffraction investigate and measure residual stress inside …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/88836
note: Development of Friction Stir Welding on Large Multi-Welded Components: Residual Stress, Distortion, and Crystallographic Texture in Lap Joints of Aluminum Alloys by Nicholas Sabry Bachelor of Applied Science, University of British Columbia, 2020 A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The College of Graduate Studies (Mechanical Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) July 2024 © Nicholas Sabry, 2024 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a dissertation entitled: Development of Friction Stir Welding on Large Multi-Welded Components: Residual Stress, Distortion, and Crystallographic Texture in Lap Joints of Aluminum Alloys submitted by Nicholas Sabry in partial fulfillment of the requirements of the degree of Doctor of Philosophy Dr. Dimitry Sediako, Faculty of Applied Science Supervisor Dr. Michael Benoit, University of Waterloo Supervisory Committee Member Dr. Jian Liu, Faculty of Applied Science Supervisory Committee Member Dr. Shahria Alam, Faculty of Applied Science University Examiner Dr. Sumanth Shankar, McMaster University External Examiner iii Abstract With the growing demand for increased battery capacity and performance, a corresponding requirement for adequate cooling of the battery cells has developed. This situation requires an efficient design of coolant channels in battery trays. The battery tray houses the cells and regulates their temperature, optimizing the distance per battery kilogram. The coolant channels in the battery tray require high-pressure die casting (HPDC) to create. However, the HPDC process is limited, and enclosed geometries for coolant flow cannot be created. Therefore, the coolant channels must be sealed with thin aluminum plates post-casting. A liquid seal is created by joining the aluminum plates to the HPDC component utilizing friction stir welding (FSW). FSW …
has type: Thesis/Dissertation
date issued: 2024-09
is shown at: 10.14288/1.0444948
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution 4.0 International
rights URI: http://creativecommons.org/licenses/by/4.0/
scholar level: Graduate
contributor: Sediako, Dimitry
type: Text
type: Still Image
identifier URI: http://hdl.handle.net/2429/88836