ENHANCING DISPERSION OF CARBON NANOTUBES WITHIN METAL MATRIX COMPOSITES
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Authors
Ruud, Margaret C.
Subjects
cold spray
carbon nanotube
CNT
composite
metal matrix composite
carbon nanotube
CNT
composite
metal matrix composite
Advisors
Ansell, Troy
Date of Issue
2023-06
Date
Publisher
Monterey, CA; Naval Postgraduate School
Language
Abstract
The dispersion of carbon nanotubes (CNTs) in an aluminum (Al) metal matrix composite (MMC) was explored in this thesis. CNTs have demonstrated strong and lightweight properties, making them a promising candidate for composite development in maritime, aeronautical, and aerospace industries. Different methods for combining CNTs with Al powder were tested including high energy ball milling (HEBM), cryomilling, and wet chemistry methods. The powders were analyzed via scanning electron microscopy (SEM) to determine which method maximizes CNT dispersion while minimizing breakage or agglomerations. It was found that wet chemistry ultrasonication in acetone created a powder composite with the smallest CNT agglomerations. The HEBM at 1 to 2 ball to powder ratio (BPR) was the next best dispersion technique. The powders that demonstrate adequate dispersion were selected for cold spray onto 6061 aluminum alloy substrate bars. Cold spray has the distinct advantage of deformation at low temperatures avoiding the heat-induced defects inherent in welding. Composite powders of 1, 2, and 3 vol% CNT for the HEBM and the acetone dispersion techniques were mixed and cold sprayed. The cold-sprayed formulations were tested for corrosion and wear resistance. The deposition efficiency of these coatings, especially for the ultrasonicated powders, was extremely low and requires further parameter optimization to obtain usable mechanical performance results.
Type
Thesis
Description
Series/Report No
Department
Mechanical and Aerospace Engineering (MAE)
Organization
Identifiers
NPS Report Number
Sponsors
Funding
Format
Citation
Distribution Statement
Approved for public release. Distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.