About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Bulk Metallic Glasses XX
|
Presentation Title |
Measurements from the Gap: Viscosity and Wave Speed Measurements in the Supercooled Liquid Region |
Author(s) |
Robert Dale Conner, Stefan Lohaus, Rebecca Stevens, Joseph Serrano |
On-Site Speaker (Planned) |
Rebecca Stevens |
Abstract Scope |
Deformation and flow behavior in bulk metallic glasses (BMGs) are well characterized at temperatures below the glass transition temperature and in the molten liquid by conventional methods, e.g. beam bending and rotating-cup viscometry. However, data is virtually absent in the supercooled liquid (SCL) region, due to the quick onset of crystallization limiting the time available for measurements. We developed an experimental setup, based on rapid discharge heating, to determine the viscosity and shear modulus of Pd-based and Ni-based BMGs in the SCL region. Shear moduli are determined from ultrasonic wave speeds measurements on heated samples, and the viscosity by tracking their deformation under an applied pressure. These are missing quantities for validating existing theories on the relaxation kinetics and rheology of metallic glasses in the SCL region, such as the Cooperative Shear Model. This work is supported by NSF award 1710741 |
Proceedings Inclusion? |
Planned: |