Viscosity of Ternary Co81(B,Si)19 and Co75(B,Si)25 Melts

The temperature dependences of the kinematic viscosity of ternary Co81(B,Si)19 and Co75(B,Si)25 melts are studied. The polytherms of the liquid alloys measured on heating and on cooling coincide and are well described by the exponential Arrhenius equation. These polytherms are used to construct concentration dependences of the ternary alloy viscosity for quasi-binary Сo81B19–Co81Si19 and Сo75B25–Co75Si25 sections at fixed temperatures. The viscosity isotherms of the quasi-binary sections are close to the additive sum of the viscosities of the binary alloys with insignificant positive deviation. The concentration dependences of the dynamic viscosity of the Сo81B19–Co81Si19 and Сo75B25–Co75Si25 melts are calculated by seven equations based on the data on the thermodynamic properties of a melt and/or the physical properties of its components. The Kozlov–Romanov–Petrov equation ensures the best coincidence with the experimental data for both the systems.