Reliable data for high-temperature viscosity and surface tension: results from a European project

Abstract

Results are reported of work carried out for the European Commission under contract number MATI CT 940006, between 1994 and 1998. The project provided recommended surface tension-temperature relationships for copper and nickel samples prepared by cold crucible melting to ±3%, by the levitation and sessile drop methods, and values were also obtained for iron and gold in preliminary studies. For copper, (γ/N m -1 ) = 1.304 - 0.289 × 10 -3 [(θ - 1083)/°C]; for nickel, (y/ N m -1 ) = 1.781 - 0.285 x 10 -3 [(θ - 1455)/°C]. Comparison of terrestrial measurements with those made in microgravity have shown that the Cumming's equation is a reliable and satisfactory method of correcting the surface tensions derived with the levitated drop method for the effect of electromagnetic pressure. For measurements with an oscillating cylinder viscometer, recommended viscosity-temperature relationships are given for copper, nickel, and iron. For copper, log 10 (η/mPa s) = -0.2791 + [1245.5/(T/K)]; for nickel, log 10 (η/mPa s) = -0.5038 + [2029/(T/K)]; and for iron, log 10 (η/mPa s) = -0.6494 + [2568/(T/K)].