Enhancing Dispersion of Carbon Nanotubes within Metal Matrix Composites
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 volume percent 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2023
- Accession Number
- AD1213629
Entities
People
- Margaret C Ruud
Organizations
- Naval Postgraduate School