Date Approved
1-30-2024
Embargo Period
1-29-2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy (Ph.D.)
Department
Chemical Engineering
College
Henry M. Rowan College of Engineering
Funder
US Army Research Laboratory
Advisor
Joseph F. Stanzione, III, Ph.D. & Francis M. Haas, Ph.D.
Committee Member 1
Aaron T. Nardi
Committee Member 2
Isaac M. Nault, Ph.D.
Committee Member 3
James A. Newell, Ph.D.
Keywords
cold spray technology, polymer coatings
Subject(s)
Coating processes
Disciplines
Chemical Engineering | Engineering
Abstract
Cold spray technology lends itself as a versatile process to rapidly apply quality polymer coatings to various substrates; barring limited, although clearly demonstrated, success. The limited success of polymer sprays is a result of modern cold spray knowledge originating from studies with metals. Thus, a deeper understanding of how polymers behave in cold spray is needed to make polymer cold spray a commercially viable process. Various tools are used in this dissertation to progress the fundamental understanding of polymer cold spray as it relates to general processing parameters with a focus on characteristics that do not occur in metals. Polymer chain length is identified as a critical factor dictating the behavior of polymers impacting at cold spray-like velocities. The effects of slow heat transfer in polymer particles compared to metals is investigated using computational modeling. Unlike metals, intraparticle thermal gradients occur in polymers that are demonstrated to influence particle deformation. Particle temperature, substrate temperature, and velocity effects are demonstrated using cold spray experiments. Increased particle velocities are demonstrated to improve spray properties, contrary to suggestions made in previous literature. This improvement is attributed to polymer viscoelasticity. Viscoelasticity is elucidated using light gas gun-accelerated polymer projectiles and high-speed videography. Results indicate that viscoelastic impact behavior is a key limiting factor to polymer cold spray that is not present in metals.
Recommended Citation
Bacha, Tristan, "TOWARDS A FUNDAMENTAL UNDERSTANDING OF THE POLYMER COLD SPRAY PROCESS" (2024). Theses and Dissertations. 3192.
https://rdw.rowan.edu/etd/3192
