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Author ORCID Identifier


Open Access Dissertation

Document Type


Degree Name

Doctor of Philosophy (PhD)

Degree Program

Mechanical Engineering

Year Degree Awarded


Month Degree Awarded


First Advisor

Jae-Hwang Lee


Cold spray is an additive manufacturing process that enables the deposition of metals, ceramics, polymers, and other materials below the melting point of the feedstock powder, resulting in a solid-state consolidation. Ultra-high strain rates in the orders of 106 s-1 and beyond are involved in this consolidation process. In recent years, this extreme process has been studied extensively to fundamentally understand the bonding dynamics and improve the deposition efficiency and performance of deposited materials. Furthermore, understanding the dynamic characteristics of the materials can extend our fundamental knowledge of the materials at the ultra-high extreme strain rate regime. The current study investigates the extreme dynamic behavior of metallic systems through micro-ballistic single-particle collisions. The micro-ballistic collisions of the microparticles at these extreme strain rates are achieved by the advanced laser-induced projectile impact test (α-LIPIT). The high strain rate nonlinear dynamic response of the materials as a function of material and process parameters influencing the cold spray process, such as substrate oxide layer, oxide/hydroxide layer of the microparticles, and elevated temperatures, are systematically quantified through this controlled experimental study. The collision dynamics and dynamic response of the materials can help us understand the materials science occurring at the interface of both the feedstock powders and the target substrates. Additionally, as material properties and deformation dynamics are strain-rate-dependent, our studies are also performed to understand material response at a wide range of strain rates. Thus, our knowledge of the rate-dependent mechanisms is extended to ultra-high strain rate plastic deformation processes and the strength of metals at both the quasi-static and high strain rate regimes.


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