Rheology and ultrasonic properties of metallic glass-forming liquids (2009)
Demetriou, Marios D., Johnson, William L., Samwer, Konrad
The flow of metallic glass-forming liquids can be modeled as configurational hopping between inherent states across energy barriers that are assumed to be on average sinusoidal. Such treatment gives...
Glassy steel optimized for glass-forming ability and toughness (2009)
Demetriou, Marios D., Kaltenboeck, Georg, Suh, Jin-Yoo, Garrett, Glenn, Floyd, Michael, Crewdson, Chase, ...
An alloy development strategy coupled with toughness assessments and ultrasonic measurements is implemented to design a series of iron-based glass-forming alloys that demonstrate improved...
Coarse-grained description of localized inelastic deformation in amorphous metals (2009)
Demetriou, Marios D., Johnson, William L., Samwer, Konrad
The sequence of shear transformation events that lead to a shear band transition in amorphous metals is described by a spatially random coarse-grained model calibrated to obey the thermodynamic...
Injection molding metallic glass (2009)
Wiest, Aaron, Harmon, John S., Demetriou, Marios D., Conner, R. Dale, Johnson, William L.
Advances in alloy development have produced the Zr_(35)Ti_(30)Be_(27.5)Cu_(7.5) alloy with a crystallization–glass transition temperature, ΔT, of 165 °C. This alloy’s large supercooled liquid...
Hofmann, Douglas C., Suh, Jin-Yoo, Wiest, Aaron, Lind, Mary Laura, Demetriou, Marios D., Johnson, William L.
The mechanical properties of bulk metallic glasses (BMGs) and their composites have been under intense investigation for many years, owing to their unique combination of high strength and elastic...
Stochastic Metallic-Glass Cellular Structures Exhibiting Benchmark Strength (2008)
Demetriou, Marios D., Veazey, Chris, Harmon, John S., Schramm, Joseph P., Johnson, William L.
By identifying the key characteristic “structural scales” that dictate the resistance of a porous metallic glass against buckling and fracture, stochastic highly porous metallic-glass structures...
Hachenberg, Jörg, Bedorf, Dennis, Samwer, Konrad, Richert, Ranko, Kahl, Annelen, Demetriou, Marios D., ...
This paper provides evidence that the physical aging of deeply and rapidly quenched metallic glasses is promoted by the Johari–Goldstein slow beta relaxation, resulting in a significant...
High porosity metallic glass foam: A powder metallurgy route (2007)
Demetriou, Marios D., Schramm, Joseph P., Veazey, Chris, Johnson, William L., Hanan, Jay C., Phelps, Nicholas B.
A powder metallurgy route to the fabrication of metallic glass foam is introduced. The method involves consolidating metallic glass powder blended with blowing agent particulates to produce...
Anelastic to Plastic Transition in Metallic Glass-Forming Liquids (2007)
Harmon, John S., Demetriou, Marios D., Johnson, William L., Samwer, Konrad
The configurational properties associated with the transition from anelasticity to plasticity in a transiently deforming metallic glass-forming liquid are studied. The data reveal that the underlying...
Rheology and ultrasonic properties of Pt57.5Ni5.3Cu14.7P22.5 liquid (2007)
Harmon, John S., Demetriou, Marios D., Johnson, William L.
The equilibrium and nonequilibrium viscosity and isoconfigurational shear modulus of Pt57.5Ni5.3Cu14.7P22.5 supercooled liquid are evaluated using continuous–strain-rate compression experiments and...
Harmon, John S., Demetriou, Marios D., Johnson, William L., Tao, Min
The change in the configurational enthalpy of metallic glass forming liquids induced by mechanical deformation and its effect on elastic softening is assessed. The acoustically measured shear modulus...
Strong configurational dependence of elastic properties for a binary model metallic glass (2006)
Duan, Gang, Lind, Mary Laura, Demetriou, Marios D., Johnson, William L., Çağin, Tahir, ...
In this work, the strong dependence of elastic properties on configurational changes in a Cu–Zr binary metallic glass assessed by molecular dynamics simulations is reported. By directly evaluating...
Cooperative Shear Model for the Rheology of Glass-Forming Metallic Liquids (2006)
Demetriou, Marios D., Harmon, John S., Tao, Min, Duan, Gang, Samwer, Konrad, Johnson, William L.
A rheological law based on the concept of cooperatively sheared flow zones is presented, in which the effective thermodynamic state variable controlling flow is identified to be the...
Synthesis method for amorphous metallic foam (2004)
Schroers, Jan, Veazey, Chris, Demetriou, Marios D., Johnson, William L.
A synthesis method for the production of amorphous metallic foam is introduced. This method utilizes the thermodynamic stability and thermoplastic formability of the supercooled liquid state to...
Modeling the transient flow of undercooled glass-forming liquids (2004)
Demetriou, Marios D., Johnson, Wiliam L.
n a recent experimental study on flow behavior of Vitreloy-1 (Zr41.25Ti13.75Cu12.5Ni10Be22.5), three distinct modes of flow are suggested: Newtonian, non-Newtonian, and localized flow. In a...
Hofmann, Douglas C., Suh, Jin-Yoo, Wiest, Aaron, Lind, Mary-Laura, Demetriou, Marios D., Johnson, William L.
The mechanical properties of bulk metallic glasses (BMGs) and their composites have been under intense investigation for many years, owing to their unique combination of high strength and elastic...