About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
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Heterostructured and Gradient Materials (HGM IV): Tailoring Heterogeneity for Superior Properties
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Presentation Title |
Chemical Gradients to Control Stability and Mechanical Behavior in Nanostructured Pt-Au |
Author(s) |
Brad L. Boyce, David Adams, Khalid Hattar, Remi Dingreville, Riley Parrish, Fadi Abdeljawad |
On-Site Speaker (Planned) |
Brad L. Boyce |
Abstract Scope |
Most heterogeneous nanostructured metals are produced by imposed deformation gradients, such as shot peening or surface mechanical attrition. But microstructural tailoring can also be produced in the absence of severe plastic deformation, by varying deposition conditions or by imparting chemical gradients. Magnetron sputtered Pt-Au with Au concentrations up to 10 at% provides a pedagogical system to study compositional gradients. In the as-deposited condition, Au naturally segregates to the grain boundary and phase separates both in the grain interior and within the grain boundary. The Au stabilizes the grain boundaries against migration through both thermodynamic and kinetic effects. Under conditions of fatigue loading, the suppression of grain boundary migration leads to substantial increase in fatigue-crack initiation resistance. Ultimately, this fatigue resistance along with the surreptitious formation of tribocatalytic diamond-like carbon enable this nanostructured Pt-Au alloy to possess extreme wear resistance. |
Proceedings Inclusion? |
Planned: |
Keywords |
Nanotechnology, Mechanical Properties, Thin Films and Interfaces |