Abstract
Friction stir welding (FSW) is the preferred joining method for metal-matrix composites (MMCs). As a solid-state process, it precludes formation of the intermetallic precipitates responsible for degradation of mechanical properties in fusion welds of MMCs. The major barrier to FSW of MMCs is the rapid and severe wear of the welding pin tool, a consequence of prolonged contact between the tool and the harder reinforcements which give the material its enhanced strength. This study evaluates the effectiveness of harder tool materials to combat wear in the FSW of MMCs. The tool materials considered are O1 steel, cemented carbide (WC-Co) of the micrograin and submicrograin varieties, and WC-Co coated with diamond. The challenges which accompany the application of harder tool materials and diamond coatings in FSW are also discussed. This study represents the first use of diamond-coated tools in FSW and the first comparative evaluation of tool materials for this application.
| Original language | English |
|---|---|
| Pages (from-to) | 1807-1813 |
| Number of pages | 7 |
| Journal | Journal of Materials Engineering and Performance |
| Volume | 22 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2013 |
| Externally published | Yes |
Funding
This study was funded by a NASA GSRP Fellowship from Marshall Spaceflight Center. Materials were provided by composites manufacturer MC21, Inc. Thanks to Dr. Art Nunes of NASA MSFC, Dr. Jim Davidson and Mick Howell of Vanderbilt University (for expertise and assistance with diamond coatings), and Bob Patchin and John Fellenstein in the Vanderbilt Physics machine shop.
| Funders | Funder number |
|---|---|
| Marshall Spaceflight Center | |
| National Aeronautics and Space Administration |
Keywords
- friction stir welding
- materials selection
- metal matrix composites
- tool wear