| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Development of Light Weight Alloys and Composites
|
| Presentation Title |
Grain Boundary Relaxation in Nanocrystalline Aluminum |
| Author(s) |
Leslie T. Mushongera, Wenye Ye, Jake Hohl, Pradeep Menezes, Mano Misra |
| On-Site Speaker (Planned) |
Leslie T. Mushongera |
| Abstract Scope |
The excess free volume in grain boundaries (GBs) of pure nanocrystalline aluminum leads to grain coarsening, which degrades their desirable mechanical properties. The decoration of GBs with dopants is proposed to stabilize the nanostructure. Thermodynamic modeling is used to identify the specific dopant type with the highest potential to segregate to grain boundaries in nanocrystalline aluminum. Various elements are evaluated as potential dopants and magnesium is identified to have the highest tendency to partition preferentially to the GBs. To shed light on the stabilization mechanisms, we present results from virtual mechanical tests on nanocrystalline aluminum samples with similar grain sizes but different magnesium dopant contents. It is found that the deformation pathways are influenced by the local GB state as modified by the dopants. The segregation of magnesium decreases the excess free volume within the GB which prohibits the nucleation and propagation of intergranular cracks. |