The cold spray (CS) deposition is a solid-state process that involves layer-by-layer consolidation of predominantly metallic powders to create high-performance deposits. As with many directed energy deposition technologies, the success of CS is heavily dependent on the feedstock powder's characteristics, such as particle size, shape, composition, moisture content, and flowability. Proper control of these property and behavior metrics is crucial for consistent and efficient material processing in CS, especially given that powder quality can degrade with improper handling and storage, leading to detrimental downstream processing effects. This research aims to expand the current understanding of the relationships between powder properties, processing conditions, and deposit performance in CS by investigating the dynamic nature of metal powder quality and its influence on processability and deposit properties. The dissertation is divided into three phases: 1. Phase 1: An exploratory analysis of how repeated environmental exposure influences powder's moisture content and gravity-driven flowability. 2. Phase 2: A comprehensive investigation into the evolution of powder moisture content and flowability with environmental exposure, pinpointing particle size and morphology effects and overall implications of exposure on CS processability. 3. Phase 3: A fundamental survey of the connections between powder characteristics, rheological behavior, and their response to the CS powder feeder configuration, elucidating the impact on deposit properties and quality. Additional preliminary experimentation, including powder salt fog exposure treatments, sets the groundwork for future investigations of powder quality ramifications on CS processing. This work enables CS users to make characterization-informed processing decisions that consider the multi- faceted influences of powder quality on deposit performance, supporting current CS development efforts to achieve consistent processing through proper feedstock powder control.

Creator

• Grubbs, Jack

Colaboradores

• Pepi, Marc
• Tsaknopoulos, Kyle
• Cheng, Lin
• Hyers, Robert
• Cote, Danielle

Degree

• PhD

Unit

• Materials Science & Engineering

Publisher

• Worcester Polytechnic Institute

Identifier

• etd-108946

Advisor

• Cote, Danielle

Orcid

• https://orcid.org/0000-0002-4035-4415

Committee

• Tsaknopoulos, Kyle
• Pepi, Marc
• Hyers, Robert
• Cheng, Lin

Defense date

• 2023-04-25

Year

• 2023

Date created

• 2023-05-04

Resource type

• Dissertation

Source

• etd-108946

Rights statement

• In Copyright

Última modificación

• 2023-06-01