| Type of Document |
Master's Thesis |
| Author |
Maisano, Adam J.
|
| Author's Email Address |
amaisano@vt.edu |
| URN |
etd-01262006-162731 |
| Title |
Cryomilling of Aluminum-based and Magnesium-based Metal Powders |
| Degree |
Master of Science |
| Department |
Materials Science and Engineering |
| Advisory Committee |
| Advisor Name |
Title |
| Kampe, Stephen L. |
Committee Chair |
| Aning, Alexander O. |
Committee Member |
| Reynolds, William T. Jr. |
Committee Member |
|
| Keywords |
- Crystallite size
- Hardness
- X-ray diffraction
- Cryomilling
- Nanocrystalline materials
- Al-Mg alloys
|
| Date of Defense |
2006-01-13 |
| Availability |
unrestricted |
Abstract
Ball milling has been shown to produce nanostructures in metal powders through severe repetitive deformation. Ball milling at cryogenic temperatures (cryomilling) is more effective in this capacity due to the low temperature by slowing recovery and minimizing diffusion distances between different components. Nanostructured metals are of interest because of their unique physical and mechanical properties. The result of cryomilling is powder consisting of crystallites on the order of 30 – 50 nm. In order to characterize the properties of this material, it is often necessary to consolidate the powder, which is often difficult without causing significant grain growth. In this work, aluminum-rich and magnesium-rich alloys of varying composition are produced by cryomilling and characterized by x-ray diffraction. A novel consolidation process called high shear powder consolidation (HSPC) is used to densify as-received and as-milled powders with minimal growth. The construction of a cryomill, along with a modification for improving process yield, has provided a platform for the study of nanocrystalline metals. It has been shown that bulk nanocrystalline materials are attainable and that alloy composition influences mechanical properties.
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| Files |
| Filename |
Size |
Approximate Download Time
(Hours:Minutes:Seconds)
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56K Modem |
ISDN (64 Kb) |
ISDN (128 Kb) |
Higher-speed Access |
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AdamMaisanoMSThesis.pdf |
2.05 Mb |
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