Thermophysical properties of undercooled liquid Co-Mo alloys

Abstract

The density and the specific heat of liquid Au-Cu alloy above and below the melting temperature are investigated in a wide composition range via constant temperature and constant pressure molecular dynamics simulations. The atomic interaction of the alloy is described with the embedded-atom method (EAM). The equilibrium melting temperature is evaluated from the change in the growth direction of a crystal-liquid sandwich structure under annealing. The simulated density of the Au-Cu alloy increases linearly with decrease of the temperature, whereas the specific heat remains constant over the entire temperature range of 900-1900 K. The excess volume is calculated according to the predicted density of Au-Cu alloy. The negative value of the excess volume and the exponential concentration dependence of the specific heat indicate that the Neumann-Kopp rule does not apply to the Au-Cu binary alloy system.

Transport Properties of Undercooled Liquid Copper: A Molecular Dynamics Study

“…The difficulty of experimental efforts lies mainly in two aspects. First, the undercooled state is hard to maintain, because the contact between the metallic melt and the container wall will introduce heterogeneities and thus will induce immediate nucleation of liquid metals [3]. This problem is solved to a certain extent by the development of containerless processing techniques, for example, the electromagnetic levitation (EML) method.…”

Noncontact measurement of high-temperature surface tension and viscosity of bulk metallic glass-forming alloys using the drop oscillation technique

“…Viscosity is a kinetic parameter that determines the nucleation and growth rates of crystals in the undercooled liquid, while knowledge of surface tension of alloys is vital for studying surface segregation effects and the extent of Marangoni flow. 6 Although surface tension and viscosity data for pure metals are available in literature, 7 they are scarce for binary systems and in the case of complex glass-forming alloys a nearly complete lack of data is evident. Data are lacking especially at high temperatures because these glass-forming systems consist of highly reactive elements such as Ni, Ti, and Zr, which limit the applicability of conventional methods 7 to measure surface tension and viscosity.…”

Specific heat and related thermophysical properties of liquid Fe-Cu-Mo alloy

“…belong to this case and the electromagnetic levitation drop calorimeter is frequently employed to measure their C PL values due to its effective heating and large undercooling. For binary alloys, although the available data are still scarce, some experimental results seem to show a similar temperature-independent variation tendency according to their melting temperatures, such as Ni-Cu, Ni-Fe, Ti-Al and Co-Mo alloys [5][6][7] . Ni 70.2 Si 29.8 alloy is an exceptional case although its melting temperature is up to 1488 K [4] .…”