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ORCID
N/A
Access Type
Open Access Thesis
Document Type
thesis
Degree Program
Mechanical Engineering
Degree Type
Master of Science in Mechanical Engineering (M.S.M.E.)
Year Degree Awarded
2018
Month Degree Awarded
May
Abstract
Cold spray is a unique additive manufacturing process, where a large number of ductile metal micro particles are deposited to create new surface coatings or free-standing structures. Metallic particles are accelerated through a gas stream, reaching velocities of over 1 km/s. Accelerated particles experience a high-strain-rate microscopic ballistic collisions against a target substrate. Large amounts of kinetic energy results in extreme plastic deformation of the particles and substrate. Though the cold spray process has been in use for decades, the extreme material science behind the deformation of particles has not been well understood due to experimental difficulties arising from the succinct spatial (10 μm) and temporal scales (10 ns). In this study, using a recently developed micro-ballistic method, the advanced laser induced projectile impact test (α-LIPIT), the dynamic behavior of micro-particles during the collision is precisely defined. We observe single aluminum 6061 alloy particles, approximately 20μm in diameter, impact and rebound off of a rigid target surface over a broad range of impact speeds, temperatures, and substrate oxide film thicknesses. Through observation of the collisions, we extract characteristic information of the dynamic response of particles as well as the relationship with various parameters (e.g. surrounding temperature, particle diameter, oxide thickness, and impact velocity). By impacting a polished aluminum 6061 alloy substrate we are able to mimic the collision events that occur during cold spray deposition. The connection between the temperature increase and the oxide thickness plays a role in theorizing the cause of unexpected phenomena, such as increased rebound energies at higher temperatures. Highly-controlled single particle impacts results, are provided to calibrate and improve computational simulations as well. This, in turn, can provide insight into the underlying material science behind the cold spray process.
DOI
https://doi.org/10.7275/11928431
First Advisor
Jae-Hwang Lee
Second Advisor
David Schmidt
Third Advisor
Jonathan Rothstein
Recommended Citation
Taglienti, Carmine, "High Strain Rate Dynamic Response of Aluminum 6061 Micro Particles at Elevated Temperatures and Varying Oxide Thicknesses of Substrate Surface" (2018). Masters Theses. 668.
https://doi.org/10.7275/11928431
https://scholarworks.umass.edu/masters_theses_2/668
Included in
Dynamics and Dynamical Systems Commons, Manufacturing Commons, Materials Science and Engineering Commons, Mechanics of Materials Commons, Nanoscience and Nanotechnology Commons, Structures and Materials Commons